HomeCalculatorsChemistryMole Calculator
Chemistry calculator

Mole Calculator

Compute amount n = m/M and particle count N = n·N_A. N_A is CODATA 2018 exact. Runs locally. Not molarity and not Henderson–Hasselbalch.

Instant result
Result
—

Enter values to calculate.

Inputs—
Mode—
Formula—
Trust summary CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance · n = m/M and N = n N_A, + O3 mpmath tabulated mole amount.
Input interpretation
Enter values to calculate.
Result
—
Verified scope
n = m/M and N = n N_A, + O3 mpmath tabulated mole amount.
Assurance
Engineering
Declared partition coverage
PASS · 8/8 declared partitions (alias, zero, to-mass, from-particles, to-particles, awkward, from-mass, invalid-domain) · Matrix
Deferred
Not molarity and not a buffer.
Numerical scope
O2: n = m/M and N = n N_A vs a separate-module identity (≤2 ULP). Not molarity. ≤2 ULP vs O3 applies only to the published tabulated mole vectors. Not molarity.
Known limitations
  • Core CVP does not include live graph, viewport, or pointer interaction.
Model
Amount of substance from mass or particle count, and the inverse mass and particle relations.
Scope
n = m/M
Verification
Engine tested · Source checked · v1.0.1 · CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance · n = m/M and N = n N_A, + O3 mpmath tabulated mole amount.· View Manifest · CVP overview · Specification
Versions
Calculation 1.0.1 · CVP protocol 1.0.0-proposed · Evidence 2026-09-25.o2-o3
Verification revision
2026-09-25.o2-o3 · 1/1 property · digest d59a4c74e31c
Legacy regression
12/12 tests · Production surface contract 5/5
Trust layers
Verification VERIFIED · Production CURRENT · Overall CVP state: VERIFIED under CVP 1.0.0-proposed
Reference
O1 model · O3 expected_values · O3 numerical_behavior · O2 expected_values · O2 numerical_behavior
Interfaces
PASS · UI (SSR) / REST / MCP — ui-ssr is query-result HTML, not a live browser session. Error-path engine·REST·MCP 1/1 (status, code, calculation_version). SSR compared on URL-canonical requested calculations; empty query is idle (not an error) and JSON-typed object/array inputs are REST/MCP-only.
Supplemental domain review
Not performed
Named expert review
Not performed
CVP suite
4/4 golden · 5/5 CVP boundary · 5/5 invalid · 1/1 property · 1/1 metamorphic · 8/8 O3 · 2/2 cross-interface · 5/5 CVP contract · Manifest
Sources
Sources
Evidence
1 legacy golden · 6 legacy boundary · legacy regression suite · 4/4 oracle-backed golden · 5/5 invalid · Artifact integrity PASS
This calculator CURRENT · Public schema 1.0.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓
Semantic contract
PASS
Full verification

Manifest identity, reference classes, interfaces, suite, and production records.

Formulas

Core equations used by this calculator.

From massn = m / M
AvogadroN = n · N_A
iLab units: mass in grams, M in g/mol, n in mol. This page is not molarity c = n/V.

How to use

1

Choose mass or particles

m → n needs mass and M. N → n needs an entity count.

2

Enter the known values

M must be greater than zero. Mass, amount, and particle count may be zero.

3

Read n and N

n = m/M. N = n·N_A.

Example calculations

Common configurations with formula and result.

ϟ

Two moles of water-like M

m=36.03 g, M=18.015 g/mol

n = 36.03 / 18.015
n=2 mol
ϟ

One mole of entities

N = N_A

n = N / N_A
n=1 mol

Mole calculator specification

Version 1.0.1 · Engine tested

Calculation status

Review policy · Evidence

Definition
Amount of substance n = m/M. Entity count N = n·N_A with N_A = 6.02214076×10²³ mol⁻¹ (CODATA 2018 exact).
What it calculates
Amount of substance from mass or particle count, and the inverse mass and particle relations.
Inputs
  • mode?
  • mass
  • molar_mass
  • amount
  • particles
Outputs
  • amount
  • mass?
  • particles?
  • N_A
Formula
n = m/M; N = n·N_A
Assumptions
  • n = m/M
  • N = n·N_A
  • N_A = 6.02214076e23 (CODATA 2018 exact)
  • Lab units g, g/mol, mol
  • Not molarity or dilution
  • Not ICE or Henderson–Hasselbalch
Units
  • g
  • g/mol
  • mol
  • count
Boundary conditions
  • from_mass missing mass or molar_mass → MISSING_REQUIRED_INPUT
  • molar_mass ≤ 0 → VALUE_MUST_BE_POSITIVE
  • unknown mode → INVALID_MODE
  • mass, amount, or particles < 0 → VALUE_OUT_OF_RANGE
Example
mass=36.03 molar_mass=18.015 → n=2
Validation cases

3 published on this page · 12/12 tests · Production surface contract 5/5 · View evidence

  • mass=36.03 molar_mass=18.015 → n=2
  • mode=from_particles particles=N_A → n=1
  • molar_mass=0 → VALUE_MUST_BE_POSITIVE
Sources
Calculation version
1.0.1

Background

Interpretation and common distinctions.

Compute amount of substance from mass or particle count.

Supported and not supported

Supported — n = m/M and N = n·N_A · API chemistry.mole.amount

Not supported — molarity, dilution, ICE, Henderson–Hasselbalch, rewriting /convert/chemistry

Agent / API notes

Capability id: chemistry.mole.amount · tool id: mole · pin 1.0.1.

{ "mode": "from_mass", "mass": 36.03, "molar_mass": 18.015 }

Other modes: to_mass, from_particles, to_particles. Errors: MISSING_REQUIRED_INPUT, INVALID_NUMBER, VALUE_MUST_BE_POSITIVE, VALUE_OUT_OF_RANGE, INVALID_MODE.

Calculator URL is /calc/chemistry/mole. Converters stay on /convert/chemistry.

Other calculators in this family: Molarity, Henderson–Hasselbalch, pH .

c Molarity › pH Henderson–Hasselbalch › pH pH ›

Frequently asked questions

Key distinctions behind the calculation.

Is this molarity?

No. Molarity c = n/V is /calc/chemistry/molarity. This page is amount of substance.

Does this rewrite the chemistry converters?

No. /convert/chemistry pair pages such as ppm stay converters. This page is amount of substance.

What is N_A?

The Avogadro constant 6.02214076×10²³ mol⁻¹, exact in CODATA 2018.

Where does this run?

Locally in the browser by default. REST and MCP call the same chemistry-engine mole wrapper.