Calculators
Math calculators
148 tools
Arithmetic, percentages, trigonometry, and more.
Browse by topic
Family pages are registry-driven. Calculator URLs stay /calc/math/…
- Basic Arithmetic Add, subtract, multiply, divide, fractions, and scientific notation. · 6 tools
- Powers, Roots & Logarithms Exponents, roots, log, ln, antilog, and exponential growth. · 7 tools
- Number Theory & Discrete Math GCF, LCM, factorial, permutations and combinations, Euclidean remainder, modular inverse, sequences, and prime factorization. · 11 tools
- Algebra & Equations Quadratic formula, linear ax + b = rhs, polynomial roots, small linear systems, and matrix det / inverse / rank / LU / QR / SVD / least squares / RREF / condition number / eigen. · 26 tools
- Trigonometry & Triangles Sin, cos, tan, inverse trig, and the general triangle solver. · 8 tools
- Geometry Pythagorean theorem, general triangles, circles, and coordinate geometry. · 45 tools
- Complex Numbers Rectangular and polar arithmetic, integer powers, nth roots, and Euler form. · 5 tools
- Numerical Calculus Numerical roots, trapezoid/Simpson/Gauss integrals, interpolation, derivatives, and 1-D minimization. Not symbolic CAS. · 38 tools
Popular
Featured tools from the Family registry.
- Sum Calculator Add a list of numbers (sum), see the mean, or work long addition with place-value steps. Paste values separated by commas, spaces, or new lines — decimals and negatives.
- Fractions Calculator Add, subtract, multiply, or divide fractions and mixed numbers with step-by-step LCD work. Free online tool — no sign-up. Runs locally in your browser.
- Scientific Notation Calculator Convert numbers to scientific, E, and engineering notation. Free online tool — no sign-up. Mobile-friendly and privacy-first. Runs locally in your browser.
- Percentage Calculator Calculate percentages, percentage of a number, and “what percent is X of Y” with clear arithmetic steps. Runs locally in your browser. Try it free.
- Ratio Calculator Simplify ratios and scale quantities that stay in proportion. Runs locally in your browser. Free online tool — no sign-up. No account needed.
- Log Calculator Evaluate logarithms (common, natural, or arbitrary base) for x > 0. Fast local calculation with shareable, machine-readable results.
- Exponent Calculator Calculate aⁿ for a real base and exponent. Fast local calculation with shareable, machine-readable results.
- Square Root Calculator Calculate the principal square root √x. Fast local calculation with shareable, machine-readable results.
Basic Arithmetic
Add, subtract, multiply, divide, fractions, and scientific notation.
- Division Calculator Divide numbers with quotient, remainder, and decimal results for quick arithmetic checks. Runs locally in your browser. Free online tool — no sign-up.
- Fractions Calculator Add, subtract, multiply, or divide fractions and mixed numbers with step-by-step LCD work. Free online tool — no sign-up. Runs locally in your browser.
- Multiplication Calculator Multiply two numbers instantly, or see long multiplication with partial products, carrying, decimals, and sign rules. Runs locally in your browser.
- Scientific Notation Calculator Convert numbers to scientific, E, and engineering notation. Free online tool — no sign-up. Mobile-friendly and privacy-first. Runs locally in your browser.
- Subtraction Calculator Subtract minuend − subtrahend to get the difference. Free online tool — no sign-up. Clear formulas and worked examples. Interactive calculations run locally in your browser.
- Sum Calculator Add a list of numbers (sum), see the mean, or work long addition with place-value steps. Paste values separated by commas, spaces, or new lines — decimals and negatives.
Percent, Ratio & Proportion
Percentage, percent change, percent error, and ratios.
- Percent Error Calculator Compute percent error between experimental and accepted values for lab and measurement checks. Interactive calculations run locally; shared URLs and REST use the same engine. Free — no sign-up.
- Percentage Calculator Calculate percentages, percentage of a number, and “what percent is X of Y” with clear arithmetic steps. Runs locally in your browser. Try it free.
- Percentage Change Calculator Calculate the percentage increase or decrease from an initial value to a final value. You can also solve for the initial or final value. Free online — no sign-up.
- Ratio Calculator Simplify ratios and scale quantities that stay in proportion. Runs locally in your browser. Free online tool — no sign-up. No account needed.
Powers, Roots & Logarithms
Exponents, roots, log, ln, antilog, and exponential growth.
- Antilog Calculator Calculate the antilogarithm: raise base b to power y. Fast local calculation with shareable, machine-readable results.
- Exponent Calculator Calculate aⁿ for a real base and exponent. Fast local calculation with shareable, machine-readable results.
- Exponential Growth Calculator Model exponential growth or decay from initial value, rate, and time. Runs locally in your browser. Free online tool — no sign-up. Try it free.
- Log Calculator Evaluate logarithms (common, natural, or arbitrary base) for x > 0. Fast local calculation with shareable, machine-readable results.
- Natural Log (ln) Calculator Calculate ln(x) = log_e(x) for x > 0. Fast local calculation with shareable, machine-readable results.
- Root Calculator Calculate the principal real nth root ⁿ√a. Fast local calculation with shareable, machine-readable results.
- Square Root Calculator Calculate the principal square root √x. Fast local calculation with shareable, machine-readable results.
Number Theory & Discrete Math
GCF, LCM, factorial, permutations and combinations, Euclidean remainder, modular inverse, sequences, and prime factorization.
- Arithmetic Sequence Calculator Nth term and partial sum of an integer arithmetic sequence. Same engine as Sequence. Not geometric. Runs locally.
- Factorial Calculator Calculate n! for integers 0 ≤ n ≤ 5000. Fast local exact integers with shareable, machine-readable results.
- Fibonacci Calculator Fibonacci numbers F_n for n ≤ 1000. F_0=0, F_1=1. Same engine as Sequence. Exact BigInt. Runs locally.
- GCF Calculator Find the GCF, GCD, or HCF of two or more integers. Exact BigInt Euclidean fold with factor and prime cross-checks. Free, no sign-up.
- Geometric Sequence Calculator Nth term and partial sum of an integer geometric sequence. Same engine as Sequence. Not arithmetic. Runs locally.
- LCM Calculator Find the LCM of two or more integers with exact arithmetic and independent verification. Free, no sign-up.
- Modular Inverse Calculator Modular inverse of a modulo m when gcd(a,m)=1. Same engine as Euclidean remainder. Not a second GCF page. Runs locally.
- Modulo Calculator Integer remainder with a = q·m + r and 0 ≤ r < |m|. Euclidean convention, not JavaScript truncated %.
Algebra & Equations
Quadratic formula, linear ax + b = rhs, polynomial roots, small linear systems, and matrix det / inverse / rank / LU / QR / SVD / least squares / RREF / condition number / eigen.
- Absolute Value Calculator Solve |ax + b| = rhs. Same engine as Linear Equation. Two solutions when rhs > 0; empty when rhs < 0. Not quadratic. Not a second engine. Not CAS. Runs locally.
- Absolute Value Inequality Calculator Solve |ax + b| ○ rhs for ○ in {<, ≤, >, ≥}. Same engine as Linear Equation. Inside the branches is an interval; outside is a union. Not quadratic. Not a second engine. Not CAS. Runs locally.
- Column Space Calculator Column space (image) of a small real square matrix from RREF pivot columns. Same engine as Linear System. Trivial image is {0}. Left-nullspace is a sibling. Runs locally.
- Condition Number Calculator κ₁(A) = ‖A‖₁ ‖A⁻¹‖₁ for a small real square matrix. Same engine as Linear System. Singular matrices return infinite. Not a 2-norm product. Runs locally.
- Cubic Equation Calculator Cardano / trigonometric closed form for a real cubic. Same engine as Polynomial Roots. Three real roots or one real plus a conjugate pair. Not Ferrari. Not a second cubic engine. Runs locally.
- Least Squares Calculator Linear least squares for a small real square system. Full rank uses QR; rank-deficient uses SVD. Same engine as Linear System. Not Statistics regression. Runs locally.
- Left Nullspace Calculator Left-nullspace (cokernel) of a small real square matrix as ker(Aᵀ). Same engine as Linear System. Trivial left kernel is {0}. Not Jordan form. Runs locally.
- Linear Equation Calculator Solve ax + b = rhs for x. Identity and inconsistent cases when a = 0. Inequality /linear-inequality. Absolute value /absolute-value. Not the quadratic formula. Runs locally.
Trigonometry & Triangles
Sin, cos, tan, inverse trig, and the general triangle solver.
- Arccos Calculator Calculate arccos(x) = cos⁻¹(x) for x in [−1, 1]. Fast local calculation with shareable, machine-readable results.
- Arcsin Calculator Calculate arcsin(x) = sin⁻¹(x) for x in [−1, 1]. Fast local calculation with shareable, machine-readable results.
- Arctan Calculator Calculate arctan(x) = tan⁻¹(x) for any real x. Fast local calculation with shareable, machine-readable results.
- Cos Calculator Calculate cos(θ) in degrees or radians. Fast local calculation with shareable, machine-readable results.
- Pythagorean Theorem Calculator Solve a right triangle with a² + b² = c². Enter any two of legs a, b and hypotenuse c to find the third side, plus area and perimeter. Try it free.
- Sin Calculator Calculate sin(θ) in degrees or radians. Fast local calculation with shareable, machine-readable results.
- Tan Calculator Calculate tan(θ) = sin(θ)/cos(θ) in degrees or radians. Fast local calculation with shareable, machine-readable results.
- Triangle Solver Solve a Euclidean triangle from SSS, SAS, ASA, AAS, or SSA (ambiguous case). Not the Pythagorean-only calculator. Runs locally.
Geometry
Pythagorean theorem, general triangles, circles, and coordinate geometry.
- Angle Between Lines Calculator Acute angle between two plane lines, each given by two points. Parallel is 0°. Perpendicular is 90°. Degenerate points are invalid. Same engine as Coordinate Geometry. Not a second engine. Not CAS. Runs locally.
- Annulus Calculator Annulus A = π(R² − r²) and P = 2π(R + r) with outer R > inner r. Same engine as Plane Geometry. Not /circle. Not a square. Not CAS. Runs locally.
- Circle Calculator Compute diameter, circumference, and area from r, or arc and sector from a central angle. Not the Pythagorean page. Runs locally.
- Cone Calculator Right circular cone V = (1/3)πr²h and slant l = √(r²+h²). Same engine as Solid Geometry. Not ISO 5167-5. Not CAS. Runs locally.
- Conic Section Calculator Axis-aligned ellipse, parabola, and hyperbola in standard form. Discovery /ellipse, /parabola, /hyperbola. Not the circle-only page. Not coordinate geometry. Not CAS. Runs locally.
- Coordinate Geometry Calculator Distance, midpoint, and slope of two points in the plane. Line through two points is /line-equation. Point-to-line distance is /point-line-distance. Intersection is /line-intersection. Angle is /angle-between-lines. Not the Pythagorean-only page. Runs locally.
- Cross Product Calculator Vector product u × v in R³. 2-D uses uz = vz = 0. Same engine as Vector. Not a matrix. Not CAS. Runs locally.
- Cylinder Calculator Right circular cylinder V = πr²h and A = 2πr(r+h). Same engine as Solid Geometry. Not CAS. Runs locally.
Complex Numbers
Rectangular and polar arithmetic, integer powers, nth roots, and Euler form.
- Complex Number Calculator Add, subtract, multiply, divide complex numbers; convert rectangular ↔ polar; integer powers, nth roots, and Euler form. Not a CAS. Runs locally.
- Complex Polar Calculator Convert a complex number between rectangular (re, im) and polar (r, θ°) form. Same engine as Complex Number. Not a CAS. Runs locally.
- Complex Power Calculator Integer power of a complex number via De Moivre. Same engine as Complex Number. Not a CAS. Not i^i. Runs locally.
- Complex Roots Calculator All n nth-roots of a complex number via De Moivre. Same engine as Complex Number. Not a CAS. Not the real root page. Runs locally.
- Euler Form Calculator Euler form of a complex number: z = r e^{iθ} = r (cos θ + i sin θ). Same engine as Complex Number. Not a CAS. Runs locally.
Numerical Calculus
Numerical roots, trapezoid/Simpson/Gauss integrals, interpolation, derivatives, and 1-D minimization. Not symbolic CAS.
- Bessel I Calculator I_n(x) for integer n=0…8. Same engine as Special Functions. Not W_{-1}. Not CAS. Runs locally.
- Bessel J Calculator J_n(x) for integer n=0…8. Same engine as Special Functions. Not W_{-1}. Not CAS. Runs locally.
- Bessel K Calculator K_n(x) for integer n=0…8 and x>0. Same engine as Special Functions. Not W_{-1}. Not CAS. Runs locally.
- Bessel Y Calculator Y_n(x) for integer n=0…8 and x>0. Same engine as Special Functions. Not W_{-1}. Not CAS. Runs locally.
- Beta Function Calculator Complete Euler B(x, y) = Γ(x)Γ(y)/Γ(x+y) for x>0, y>0. Same engine as Special Functions. Not incomplete beta. Not CAS. Runs locally.
- Brent Method Calculator Brent’s method (golden section plus inverse parabolic interpolation) for a minimum of a polynomial, sin, or exp on [a, b]. Same engine as One-Dimensional Optimization. Not root-finding Brent. Runs locally.
- Definite Integral Calculator Composite trapezoid, Simpson 1/3, or Gauss–Legendre of a polynomial, sin, or exp on [a, b]. Not indefinite symbolic integrate. Runs locally.
- DFT Calculator Forward DFT X[k]=Σ x[n] e^{−2πi kn/N}, N≤64, unnormalized. Same engine as Discrete Fourier Transform. Radix-2 FFT is on /fft. Not inverse, not Laplace. Runs locally.
All Math calculators
Full list for search and crawl.
- Absolute Value Calculator Solve |ax + b| = rhs. Same engine as Linear Equation. Two solutions when rhs > 0; empty when rhs < 0. Not quadratic. Not a second engine. Not CAS. Runs locally.
- Absolute Value Inequality Calculator Solve |ax + b| ○ rhs for ○ in {<, ≤, >, ≥}. Same engine as Linear Equation. Inside the branches is an interval; outside is a union. Not quadratic. Not a second engine. Not CAS. Runs locally.
- Angle Between Lines Calculator Acute angle between two plane lines, each given by two points. Parallel is 0°. Perpendicular is 90°. Degenerate points are invalid. Same engine as Coordinate Geometry. Not a second engine. Not CAS. Runs locally.
- Annulus Calculator Annulus A = π(R² − r²) and P = 2π(R + r) with outer R > inner r. Same engine as Plane Geometry. Not /circle. Not a square. Not CAS. Runs locally.
- Antilog Calculator Calculate the antilogarithm: raise base b to power y. Fast local calculation with shareable, machine-readable results.
- Arccos Calculator Calculate arccos(x) = cos⁻¹(x) for x in [−1, 1]. Fast local calculation with shareable, machine-readable results.
- Arcsin Calculator Calculate arcsin(x) = sin⁻¹(x) for x in [−1, 1]. Fast local calculation with shareable, machine-readable results.
- Arctan Calculator Calculate arctan(x) = tan⁻¹(x) for any real x. Fast local calculation with shareable, machine-readable results.
- Arithmetic Sequence Calculator Nth term and partial sum of an integer arithmetic sequence. Same engine as Sequence. Not geometric. Runs locally.
- Bessel I Calculator I_n(x) for integer n=0…8. Same engine as Special Functions. Not W_{-1}. Not CAS. Runs locally.
- Bessel J Calculator J_n(x) for integer n=0…8. Same engine as Special Functions. Not W_{-1}. Not CAS. Runs locally.
- Bessel K Calculator K_n(x) for integer n=0…8 and x>0. Same engine as Special Functions. Not W_{-1}. Not CAS. Runs locally.
- Bessel Y Calculator Y_n(x) for integer n=0…8 and x>0. Same engine as Special Functions. Not W_{-1}. Not CAS. Runs locally.
- Beta Function Calculator Complete Euler B(x, y) = Γ(x)Γ(y)/Γ(x+y) for x>0, y>0. Same engine as Special Functions. Not incomplete beta. Not CAS. Runs locally.
- Brent Method Calculator Brent’s method (golden section plus inverse parabolic interpolation) for a minimum of a polynomial, sin, or exp on [a, b]. Same engine as One-Dimensional Optimization. Not root-finding Brent. Runs locally.
- Circle Calculator Compute diameter, circumference, and area from r, or arc and sector from a central angle. Not the Pythagorean page. Runs locally.
- Column Space Calculator Column space (image) of a small real square matrix from RREF pivot columns. Same engine as Linear System. Trivial image is {0}. Left-nullspace is a sibling. Runs locally.
- Complex Number Calculator Add, subtract, multiply, divide complex numbers; convert rectangular ↔ polar; integer powers, nth roots, and Euler form. Not a CAS. Runs locally.
- Complex Polar Calculator Convert a complex number between rectangular (re, im) and polar (r, θ°) form. Same engine as Complex Number. Not a CAS. Runs locally.
- Complex Power Calculator Integer power of a complex number via De Moivre. Same engine as Complex Number. Not a CAS. Not i^i. Runs locally.
- Complex Roots Calculator All n nth-roots of a complex number via De Moivre. Same engine as Complex Number. Not a CAS. Not the real root page. Runs locally.
- Condition Number Calculator κ₁(A) = ‖A‖₁ ‖A⁻¹‖₁ for a small real square matrix. Same engine as Linear System. Singular matrices return infinite. Not a 2-norm product. Runs locally.
- Cone Calculator Right circular cone V = (1/3)πr²h and slant l = √(r²+h²). Same engine as Solid Geometry. Not ISO 5167-5. Not CAS. Runs locally.
- Conic Section Calculator Axis-aligned ellipse, parabola, and hyperbola in standard form. Discovery /ellipse, /parabola, /hyperbola. Not the circle-only page. Not coordinate geometry. Not CAS. Runs locally.
- Coordinate Geometry Calculator Distance, midpoint, and slope of two points in the plane. Line through two points is /line-equation. Point-to-line distance is /point-line-distance. Intersection is /line-intersection. Angle is /angle-between-lines. Not the Pythagorean-only page. Runs locally.
- Cos Calculator Calculate cos(θ) in degrees or radians. Fast local calculation with shareable, machine-readable results.
- Cross Product Calculator Vector product u × v in R³. 2-D uses uz = vz = 0. Same engine as Vector. Not a matrix. Not CAS. Runs locally.
- Cubic Equation Calculator Cardano / trigonometric closed form for a real cubic. Same engine as Polynomial Roots. Three real roots or one real plus a conjugate pair. Not Ferrari. Not a second cubic engine. Runs locally.
- Cylinder Calculator Right circular cylinder V = πr²h and A = 2πr(r+h). Same engine as Solid Geometry. Not CAS. Runs locally.
- Definite Integral Calculator Composite trapezoid, Simpson 1/3, or Gauss–Legendre of a polynomial, sin, or exp on [a, b]. Not indefinite symbolic integrate. Runs locally.
- DFT Calculator Forward DFT X[k]=Σ x[n] e^{−2πi kn/N}, N≤64, unnormalized. Same engine as Discrete Fourier Transform. Radix-2 FFT is on /fft. Not inverse, not Laplace. Runs locally.
- Discrete Fourier Transform Calculator Direct DFT / IDFT and radix-2 FFT / IFFT of a length-N sequence, N≤64. FFT requires N=2^k. Numpy backward: unnormalized forward, 1/N inverse. Discovery /dft, /inverse-dft, /fft, /ifft. Not Laplace. Not CAS. Runs locally.
- Division Calculator Divide numbers with quotient, remainder, and decimal results for quick arithmetic checks. Runs locally in your browser. Free online tool — no sign-up.
- Dodecahedron Calculator Regular dodecahedron V = (1/4)(15+7√5)a³ and A = 3√(25+10√5) a² from one edge. Same engine as Solid Geometry. Not an icosahedron. Not an n-gon prism. Not CAS. Runs locally.
- Dot Product Calculator Scalar product u · v = ux vx + uy vy + uz vz. Same engine as Vector. Not a matrix. Not CAS. Runs locally.
- Ellipse Calculator Standard ellipse x²/a² + y²/b² = 1. Same engine as Conic Section. a = b is a valid ellipse with e = 0; the circle-only page is /circle. Not CAS. Runs locally.
- Ellipsoid Calculator Ellipsoid V = 4/3 πabc and exact surface from three semi-axes. a = b = c is a sphere. Same engine as Solid Geometry. Not /sphere. Not the 2-D ellipse. Not CAS. Runs locally.
- Error Function Calculator erf(x) = (2/√π) ∫₀ˣ e^{−t²} dt. Same engine as Special Functions. Odd, erf(0)=0, erf(∞)→1. Not CAS. Runs locally.
- Euler Form Calculator Euler form of a complex number: z = r e^{iθ} = r (cos θ + i sin θ). Same engine as Complex Number. Not a CAS. Runs locally.
- Euler Method Calculator Forward Euler for a scalar first-order IVP y′=f(t,y). Same engine as Ordinary Differential Equation. Not RK4, not rk45, not a system. Runs locally.
- Exponent Calculator Calculate aⁿ for a real base and exponent. Fast local calculation with shareable, machine-readable results.
- Exponential Growth Calculator Model exponential growth or decay from initial value, rate, and time. Runs locally in your browser. Free online tool — no sign-up. Try it free.
- Factorial Calculator Calculate n! for integers 0 ≤ n ≤ 5000. Fast local exact integers with shareable, machine-readable results.
- FFT Calculator Radix-2 Cooley–Tukey FFT, N=2^k ≤64, unnormalized. Same engine as Discrete Fourier Transform. Numpy backward. Not a second DFT engine. Not CAS. Runs locally.
- Fibonacci Calculator Fibonacci numbers F_n for n ≤ 1000. F_0=0, F_1=1. Same engine as Sequence. Exact BigInt. Runs locally.
- Fractions Calculator Add, subtract, multiply, or divide fractions and mixed numbers with step-by-step LCD work. Free online tool — no sign-up. Runs locally in your browser.
- Frustum Calculator Right circular frustum V = (1/3)πh(R²+Rr+r²) from two radii and height. Same engine as Solid Geometry. Not /cone. Not ISO 5167-5. Not CAS. Runs locally.
- Gamma Function Calculator Γ(x) = ∫₀^∞ t^{x−1} e^{−t} dt except poles at 0, −1, −2, …. Same engine as Special Functions. Not factorial. Not CAS. Runs locally.
- Gauss Quadrature Calculator n-point Gauss–Legendre quadrature of a polynomial, sin, or exp on [a, b]. Same engine as Definite Integral. Not indefinite CAS. Runs locally.
- GCF Calculator Find the GCF, GCD, or HCF of two or more integers. Exact BigInt Euclidean fold with factor and prime cross-checks. Free, no sign-up.
- Geometric Sequence Calculator Nth term and partial sum of an integer geometric sequence. Same engine as Sequence. Not arithmetic. Runs locally.
- Golden Section Search Calculator Golden-section search for a minimum of a polynomial, sin, or exp on [a, b]. Same engine as One-Dimensional Optimization. Not Brent, not multivariate. Runs locally.
- Hyperbola Calculator Standard hyperbola x²/a² − y²/b² = 1 (horizontal) or y²/a² − x²/b² = 1 (vertical). Same engine as Conic Section. Not CAS. Runs locally.
- Icosahedron Calculator Regular icosahedron V = (5/12)(3+√5)a³ and A = 5√3 a² from one edge. Same engine as Solid Geometry. Not an octahedron. Not a dodecahedron. Not CAS. Runs locally.
- Incomplete Beta Calculator Incomplete beta B_x(a, b) = ∫₀ˣ t^{a−1}(1−t)^{b−1} dt for a>0, b>0, 0≤x≤1. Same engine as Special Functions. Not normalized sinc. Not CAS. Runs locally.
- Inverse DFT Calculator Inverse DFT x[n]=(1/N) Σ X[k] e^{2πi kn/N}, N≤64, Numpy backward. Same engine as Discrete Fourier Transform. Radix-2 FFT is on /fft. Not Laplace. Runs locally.
- Inverse FFT Calculator Radix-2 Cooley–Tukey inverse FFT, N=2^k ≤64, Numpy backward 1/N. Same engine as Discrete Fourier Transform. Not a second DFT engine. Not CAS. Runs locally.
- Inverse Laplace Calculator Inverse of the unilateral Laplace table: exp, sin, cos, step, ramp, t^n, damped sin/cos at t≥0. Same engine as Laplace Transform. Not Bromwich. Not Z. Not CAS. Runs locally.
- Inverse Z Calculator Inverse of the unilateral Z table: a^n, step, ramp, n a^n, sin, cos, damped sin/cos at integer n≥0. Same engine as Z Transform. Not residue. Not Laplace. Not CAS. Runs locally.
- Irregular Polygon Calculator Shoelace area of a simple 3–8 vertex polygon. Same engine as Plane Geometry. Not /regular-polygon. Not a triangle solver. Not CAS. Runs locally.
- Lambert W Calculator Principal real W_0(x) for x ≥ −1/e. Same engine as Special Functions. Not incomplete beta. Not CAS. Runs locally.
- Lambert W₋₁ Calculator Real W_{-1}(x) for −1/e ≤ x < 0. Same engine as Special Functions. Not incomplete beta. Not CAS. Runs locally.
- Laplace Transform Calculator Unilateral Laplace table of causal elementary pairs: exp, sin, cos, step, ramp, t^n, damped sin/cos. Evaluate F(s) or f(t). Discovery /inverse-laplace. Not DFT. Not Z. Not CAS. Runs locally.
- LCM Calculator Find the LCM of two or more integers with exact arithmetic and independent verification. Free, no sign-up.
- Least Squares Calculator Linear least squares for a small real square system. Full rank uses QR; rank-deficient uses SVD. Same engine as Linear System. Not Statistics regression. Runs locally.
- Left Nullspace Calculator Left-nullspace (cokernel) of a small real square matrix as ker(Aᵀ). Same engine as Linear System. Trivial left kernel is {0}. Not Jordan form. Runs locally.
- Line Equation Calculator Equation of the line through two plane points. Same engine as Coordinate Geometry. Vertical is x = x₁. Coincident points are invalid. Not Pythagorean. Not a second engine. Not CAS. Runs locally.
- Line Intersection Calculator Intersection of two plane lines, each given by two points. Parallel distinct lines are empty. Coincident lines are infinite. Degenerate points are invalid. Same engine as Coordinate Geometry. Not a second engine. Not CAS. Runs locally.
- Linear Equation Calculator Solve ax + b = rhs for x. Identity and inconsistent cases when a = 0. Inequality /linear-inequality. Absolute value /absolute-value. Not the quadratic formula. Runs locally.
- Linear Inequality Calculator Solve ax + b ○ rhs for ○ in {<, ≤, >, ≥}. Same engine as Linear Equation. Negative a flips the inequality. Not quadratic. Not a second engine. Runs locally.
- Linear System Calculator Solve small linear systems Ax = b, plus det, inverse, rank, LU, QR, SVD, least squares, RREF, condition number, nullspace, column space, rowspace, left-nullspace, and eigenvalues. Same engine as the matrix workspace. Not a CAS. Runs locally.
- Log Calculator Evaluate logarithms (common, natural, or arbitrary base) for x > 0. Fast local calculation with shareable, machine-readable results.
- LU Factorization Calculator Doolittle LU factorization with partial pivoting for a small real matrix. Same engine as Linear System. Not a CAS. Runs locally.
- Matrix Determinant Calculator Determinant of a small real matrix. Same engine as Linear System and the matrix workspace. Not a CAS. Runs locally.
- Matrix Eigenvalues Calculator Eigenvalues and eigenvectors of a small real matrix via the characteristic polynomial. Same engine as Linear System. Not a CAS. Runs locally.
- Matrix Inverse Calculator Inverse of a small real matrix via Gauss–Jordan. Same engine as Linear System. Singular matrices fail. Not a CAS. Runs locally.
- Matrix Rank Calculator Rank of a small real matrix via Gaussian elimination. Same engine as Linear System. Not a CAS. Runs locally.
- Modular Inverse Calculator Modular inverse of a modulo m when gcd(a,m)=1. Same engine as Euclidean remainder. Not a second GCF page. Runs locally.
- Modulo Calculator Integer remainder with a = q·m + r and 0 ≤ r < |m|. Euclidean convention, not JavaScript truncated %.
- Multiplication Calculator Multiply two numbers instantly, or see long multiplication with partial products, carrying, decimals, and sign rules. Runs locally in your browser.
- Natural Log (ln) Calculator Calculate ln(x) = log_e(x) for x > 0. Fast local calculation with shareable, machine-readable results.
- Nonlinear Equation Calculator One real root of a polynomial, sin, or exp by Newton, bisection, or secant. Same engine as Numerical Root. Not a second root engine. Not CAS. Not a system. Runs locally.
- Normalized Sinc Calculator Normalized sinc(x)=sin(πx)/(πx) with sinc(0)=1. Same engine as Special Functions. DSP / numpy convention. Not CAS. Runs locally.
- Nullspace Calculator Right nullspace of a small real square matrix from RREF. Same engine as Linear System. Trivial kernel is {0}. Left-nullspace is a sibling. Runs locally.
- Numerical Derivative Calculator Finite-difference derivative of a polynomial, sin, or exp, plus a numeric two-sided limit. Central, forward, backward, or limit. Discovery /two-sided-limit. Not symbolic d/dx. Runs locally.
- Numerical Interpolation Calculator Piecewise-linear, Lagrange, or natural cubic spline of tabulated (x, y). Not regression, not CAS. Runs locally.
- Numerical Root Calculator Find a real root of a polynomial, sin, or exp with Newton, bisection, or secant. One capability, three methods. Nonlinear discovery /nonlinear-equation. Not the nth-root page. Runs locally.
- Octahedron Calculator Regular octahedron V = (√2/3)a³ and A = 2√3 a² from one edge. Same engine as Solid Geometry. Not a tetrahedron. Not an icosahedron. Not CAS. Runs locally.
- One-Dimensional Optimization Calculator Minimize a polynomial, sin, or exp on [a, b] by golden-section search or Brent. Not multivariate, not max, not CAS. Runs locally.
- Ordinary Differential Equation Calculator Scalar first-order IVP y′=f(t,y) by Euler or classical RK4. rhs linear is y′=k y; poly is y′=p(t). Not rk45, not systems, not PDE, not CAS. Runs locally.
- Parabola Calculator Standard parabola x² = 4py (vertical) or y² = 4px (horizontal). Same engine as Conic Section. p ≠ 0. Not CAS. Runs locally.
- Parallelogram Calculator Parallelogram A = ab sin θ, P = 2(a+b), diagonals from a, b, and included angle. Same engine as Plane Geometry. Not a rectangle page. Not the fluid trapezoid. Not CAS. Runs locally.
- Percent Error Calculator Compute percent error between experimental and accepted values for lab and measurement checks. Interactive calculations run locally; shared URLs and REST use the same engine. Free — no sign-up.
- Percentage Calculator Calculate percentages, percentage of a number, and “what percent is X of Y” with clear arithmetic steps. Runs locally in your browser. Try it free.
- Percentage Change Calculator Calculate the percentage increase or decrease from an initial value to a final value. You can also solve for the initial or final value. Free online — no sign-up.
- Permutation Combination Calculator Exact P(n,k) and C(n,k) for integers 0 ≤ k ≤ n ≤ 1000. Multiplicative BigInt, local-first. Not the factorial calculator.
- Plane Geometry Calculator Rectangle, square, regular n-gon, annulus, parallelogram, isosceles trapezoid, and irregular polygon (shoelace). Discovery /rectangle, /square, /regular-polygon, /annulus, /parallelogram, /trapezoid, /irregular-polygon. Not the circle-only page. Not a triangle solver. Not solid geometry. Not /square-root. Not CAS. Runs locally.
- Point Line Distance Calculator Perpendicular distance from a plane point to the line through two points. Same engine as Coordinate Geometry. Coincident line points are invalid. Not Pythagorean. Not a second engine. Not CAS. Runs locally.
- Polynomial Evaluate Calculator Horner nested multiplication for a real polynomial at a real x. Same engine as Polynomial Roots. Not factoring. Not a second engine. Not CAS. Runs locally.
- Polynomial Roots Calculator Find all roots of a real polynomial of degree 1–8. Closed form for linear, quadratic, and cubic (Cardano); Durand–Kerner otherwise. Cubic discovery /cubic-equation. Horner evaluation /polynomial-evaluate. Not the quadratic formula page. Runs locally.
- Prime Factorization Calculator Factor n = ∏ p^e and test primality for 1 ≤ n ≤ 10^12. Trial division. One capability, two modes.
- Prism Calculator Right rectangular prism V = abh from three edge lengths. Same engine as Solid Geometry. Not a frustum. Not a pyramid. Not CAS. Runs locally.
- Pyramid Calculator Right rectangular pyramid V = abh/3 from three lengths. Same engine as Solid Geometry. Not a prism. Not a tetrahedron. Not CAS. Runs locally.
- Pythagorean Theorem Calculator Solve a right triangle with a² + b² = c². Enter any two of legs a, b and hypotenuse c to find the third side, plus area and perimeter. Try it free.
- QR Factorization Calculator Householder QR factorization of a small real matrix. Same engine as Linear System. Not a CAS. Runs locally.
- Quadratic Formula Calculator Solve ax² + bx + c = 0 with the quadratic formula. Inequality discovery /quadratic-inequality. Free online tool — no sign-up. Clear formulas and worked examples. Runs locally in your browser.
- Quadratic Inequality Calculator Solve ax² + bx + c ○ rhs for ○ in {<, ≤, >, ≥}. Same engine as Quadratic. Sign of a is the outside of the roots. Not cubic. Not a second engine. Not CAS. Runs locally.
- Ratio Calculator Simplify ratios and scale quantities that stay in proportion. Runs locally in your browser. Free online tool — no sign-up. No account needed.
- Rational Equation Calculator Solve (ax + b)/(cx + d) = rhs. Same engine as Linear Equation. Clears to linear; the pole x = −d/c is excluded. Not quadratic. Not a second engine. Not CAS. Runs locally.
- Rational Inequality Calculator Solve (ax + b)/(cx + d) ○ rhs for ○ in {<, ≤, >, ≥}. Same engine as Linear Equation. Sign chart of N·D; the pole is excluded. Not quadratic. Not a second engine. Not CAS. Runs locally.
- Rectangle Calculator Rectangle A = ab, P = 2(a+b), d = √(a²+b²). Same engine as Plane Geometry. Not Pythagorean-only. Not CAS. Runs locally.
- Regular Frustum Calculator Regular n-gon frustum V = h/3 (A+a+√(Aa)) from n, two sides, and height. Bases from Regular Polygon. Same engine as Solid Geometry. Not /frustum. Not /regular-pyramid. Not CAS. Runs locally.
- Regular Polygon Calculator Regular n-gon A = (n s²)/(4 tan(π/n)) for integer n≥3. Same engine as Plane Geometry. Not a triangle solver. Not CAS. Runs locally.
- Regular Prism Calculator Regular n-gon prism V = A h with A = (n s²)/(4 tan(π/n)) from n, side, and height. Base from Regular Polygon. Same engine as Solid Geometry. Not /prism. Not /regular-pyramid. Not CAS. Runs locally.
- Regular Pyramid Calculator Regular n-gon pyramid V = A h/3 with A = (n s²)/(4 tan(π/n)) from n, side, and height. Base from Regular Polygon. Same engine as Solid Geometry. Not /pyramid. Not a tetrahedron. Not CAS. Runs locally.
- Root Calculator Calculate the principal real nth root ⁿ√a. Fast local calculation with shareable, machine-readable results.
- Row Space Calculator Row space of a small real square matrix from nonzero RREF rows. Same engine as Linear System. Trivial rowspace is {0}. Left-nullspace is a sibling. Runs locally.
- RREF Calculator Gauss–Jordan reduced row echelon form for a small real square matrix. Same engine as Linear System. Not a CAS. Runs locally.
- Runge–Kutta Calculator Classical fourth-order Runge–Kutta for a scalar first-order IVP y′=f(t,y). Same engine as Ordinary Differential Equation. Not Euler, not rk45, not a system. Runs locally.
- Scientific Notation Calculator Convert numbers to scientific, E, and engineering notation. Free online tool — no sign-up. Mobile-friendly and privacy-first. Runs locally in your browser.
- Sequence Calculator Integer arithmetic and geometric sequences, Fibonacci (F₀=0), and linear recurrences. Exact BigInt. Not Pascal’s triangle. Runs locally.
- Simpson Rule Calculator Composite Simpson 1/3 of a polynomial, sin, or exp on [a, b]. Same engine as Definite Integral. Not indefinite CAS. Runs locally.
- Sin Calculator Calculate sin(θ) in degrees or radians. Fast local calculation with shareable, machine-readable results.
- Sinc Function Calculator Unnormalized sinc(x)=sin(x)/x with sinc(0)=1. Same engine as Special Functions. Not normalized sinc. Not CAS. Runs locally.
- Solid Geometry Calculator Right circular sphere, cylinder, cone, ring torus, conical frustum, right rectangular prism, right rectangular pyramid, regular tetrahedron, regular octahedron, regular icosahedron, regular dodecahedron, regular n-gon prism, regular n-gon pyramid, regular n-gon frustum, ellipsoid, spherical cap, spherical zone, spherical wedge, spherical lune, and spherical sector. Discovery /sphere, /cylinder, /cone, /torus, /frustum, /prism, /pyramid, /tetrahedron, /octahedron, /icosahedron, /dodecahedron, /regular-prism, /regular-pyramid, /regular-frustum, /ellipsoid, /spherical-cap, /spherical-zone, /spherical-wedge, /spherical-lune, /spherical-sector. Not the circle-only page. Not a vector. Not ISO 5167-5. Not CAS. Runs locally.
- Special Functions Calculator Real erf, erfc, Gamma, log-gamma, Bessel J_n, Y_n, I_n, and K_n, Lambert W_0 and W_{-1}, Euler beta, incomplete beta, unnormalized sinc, and normalized sinc. Discovery /error-function, /gamma-function, /bessel-function, /bessel-y, /bessel-i, /bessel-k, /lambert-w, /lambert-w-minus-1, /beta-function, /incomplete-beta, /sinc-function, /normalized-sinc. Not factorial. Not CAS. Runs locally.
- Sphere Calculator Sphere V = (4/3)πr³ and A = 4πr². Same engine as Solid Geometry. Not the circle-only page. Not CAS. Runs locally.
- Spherical Cap Calculator Spherical cap V = (1/3)πh²(3r−h) from sphere radius and cap height. h = r is a hemisphere. h = 2r is a sphere. Same engine as Solid Geometry. Not /sphere. Not CAS. Runs locally.
- Spherical Lune Calculator Spherical lune A = 2r²θ from sphere radius and dihedral angle. Same engine as Solid Geometry. Not /spherical-wedge. Not /spherical-cap. Not /sphere. Not CAS. Runs locally.
- Spherical Sector Calculator Spherical sector V = (2/3)πr²h from sphere radius and cap height. h = r is a hemisphere. h = 2r is a sphere. Same engine as Solid Geometry. Not /spherical-cap. Not /cone. Not /sphere. Not CAS. Runs locally.
- Spherical Wedge Calculator Spherical wedge V = (2/3)r³θ from sphere radius and dihedral angle. Same engine as Solid Geometry. Not /spherical-cap. Not /spherical-zone. Not /sphere. Not CAS. Runs locally.
- Spherical Zone Calculator Spherical zone V = (πh/6)(3a²+3b²+h²) from two parallel base radii and height. Same engine as Solid Geometry. Not /spherical-cap. Not /sphere. Not CAS. Runs locally.
- Spline Interpolation Calculator Natural cubic spline through tabulated (x, y). Same engine as Numerical Interpolation. Not Akima, PCHIP, or regression. Runs locally.
- Square Calculator Square A = s², P = 4s, d = s√2. Same engine as Plane Geometry. Not /rectangle. Not /square-root. Not CAS. Runs locally.
- Square Root Calculator Calculate the principal square root √x. Fast local calculation with shareable, machine-readable results.
- Subtraction Calculator Subtract minuend − subtrahend to get the difference. Free online tool — no sign-up. Clear formulas and worked examples. Interactive calculations run locally in your browser.
- Sum Calculator Add a list of numbers (sum), see the mean, or work long addition with place-value steps. Paste values separated by commas, spaces, or new lines — decimals and negatives.
- SVD Calculator Singular value decomposition of a small real square matrix. Same engine as Linear System. Least squares is a sibling discovery URL. Not a CAS. Runs locally.
- Tan Calculator Calculate tan(θ) = sin(θ)/cos(θ) in degrees or radians. Fast local calculation with shareable, machine-readable results.
- Tetrahedron Calculator Regular tetrahedron V = a³√2/12 and A = a²√3 from one edge. Same engine as Solid Geometry. Not a rectangular pyramid. Not an octahedron. Not CAS. Runs locally.
- Torus Calculator Ring torus V = 2π² R r² and A = 4π² R r with major R > tube r. Same engine as Solid Geometry. Not a sphere. Not horn or spindle. Not CAS. Runs locally.
- Trapezoid Calculator Isosceles trapezoid A = (a+b)h/2 from two bases and height. Same engine as Plane Geometry. Not /trapezoidal-rule. Not the fluid trapezoid. Not CAS. Runs locally.
- Trapezoidal Rule Calculator Composite trapezoidal rule of a polynomial, sin, or exp on [a, b]. Same engine as Definite Integral. Not the fluid trapezoid pages. Runs locally.
- Triangle Solver Solve a Euclidean triangle from SSS, SAS, ASA, AAS, or SSA (ambiguous case). Not the Pythagorean-only calculator. Runs locally.
- Two-Sided Limit Calculator Numeric two-sided limit of a polynomial, sin, or exp at a finite x. Same engine as Numerical Derivative. Not one-sided. Not L’Hôpital. Not a second engine. Runs locally.
- Vector Calculator R²/R³ magnitude, normalize, add/sub, dot, cross, angle, projection, and scalar triple product. Discovery /vector-magnitude, /dot-product, /cross-product. Not a matrix. Not CAS. Runs locally.
- Vector Magnitude Calculator Euclidean length |u| = √(ux²+uy²+uz²). Same engine as Vector. uz defaults to 0. Not a matrix. Not CAS. Runs locally.
- Z Transform Calculator Unilateral Z table of causal elementary pairs: a^n, step, ramp, n a^n, sin, cos, damped sin/cos. Evaluate X(z) or x[n]. Discovery /inverse-z. Not DFT. Not Laplace. Not CAS. Runs locally.