CVP verified calculation capability

Watts to Volts Calculation Capability

Find voltage from power and current, or from power and resistance. Reverse: watts from volts and current.

Electrical Capability ID electrical.watts_to_volts version 1.3.1 CVP VERIFIED CURRENT Engineering

Model

DC (with amps)

DC (with amps): V = P ÷ I
AC 1φ: V = P ÷ (I × PF)
AC 3φ (L-L): V = P ÷ (√3 × I × PF)
AC 3φ (L-N): V = P ÷ (3 × I × PF)
With ohms / impedance: V = √(P × R)
Volts → watts (DC): P = V × I

Modes: w-v-a · w-v-r · v-w

Inputs / Outputs

Canonical symbols for this capability. Agent schemas remain the contract.

Symbol	Quantity	Unit	Role
`a`	Power in W, or voltage in V on the reverse path	—	input
`b`	Current in A, resistance in Ω, or current in A on the reverse path	—	input
`pf`	Power factor	—	input
`phase`	single uses 1; three uses √3	—	input
`api_version`	—	—	output
`api_contract_version`	—	—	output
`spec_version`	—	—	output
`page`	Canonical calculator page URL	—	output
`links`	—	—	output

Assumptions / Validity

Declared scope for this capability. Do not use it outside this domain.

Assumptions

RMS quantities for AC
Balanced three-phase when √3 selected
Ohms path assumes real resistive (or |Z| for RF magnitude)

Example

One numerical check. The calculator page holds worked steps and FAQ.

240 W, 2 A, PF 1 → 120 V

Open this example in the calculator

Trust

CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance. Computational verification is defined by CVP. Supplemental domain review (internal) and named expert review are defined by the Review policy and do not by themselves determine CVP conformance.

CVP: CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance· View Manifest · CVP overview · Specification
Assurance: Engineering
Declared partition coverage: PASS · 4/4 declared partitions (w-v-a, w-v-r, v-w, invalid-domain)
Calculation version: 1.3.1
Verification: 13/13 calculation tests · 13/13 legacy golden · 0/0 legacy boundary
Production surface contract: 4/4
Versions: Calculation 1.3.1 · CVP protocol 1.0.0-proposed
CVP identity: 0/0 property · digest 21e542929dd0
Reference: O1 model · O2 expected_values · O2 numerical_behavior
Interfaces: PASS · UI (SSR) / REST / MCP
ui-ssr is query-result HTML, not a live browser session.
CVP suite: 3/3 golden · 1/1 CVP boundary · 1/1 invalid · 1/1 cross-interface · 4/4 CVP contract
Supplemental domain review: Not performed
Named expert review: Not performed
Version lock: Supported (409 VERSION_MISMATCH)
Artifact consistency: Build verified · 1.3.1 (workspace artifacts agree)
Review-policy tier: Engine tested — catalog token engine_tested; supplemental; not CVP status

This calculator CURRENT · Public schema 1.3.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

Call this capability

Human page, REST, and MCP share the same engine and calculation_version. Build verified hashes workspace artifacts only. After deploy, attest:production GETs canonical URLs twice — the public/cached view an Agent actually hits, and origin — including every /capabilities/{id} HTML page. Public Capability HTML version must match catalog before production attestation passes. Live Trust rows above fetch /.well-known/calculatorx-production-attestation.json and the output schema const. Build hashes: release integrity. That proves currently published page / engine / schema / evidence / MCP agree — not that a historical version is independently immutable. Reference Calculation Standard — Production surface contract 4/4.

curl -sS -X POST 'https://www.calculatorx.com/api/v1/calc/watts-to-volts' \
  -H 'Content-Type: application/json' \
  -d '{"inputs":{"a":240,"b":2,"phase":"single","pf":1,"factor":1},"calculation_version":"1.3.1"}'

{
  "inputs": {
    "a": 240,
    "b": 2,
    "phase": "single",
    "pf": 1,
    "factor": 1
  },
  "calculation_version": "1.3.1"
}

POST /api/v1/calc/watts-to-volts. This is a POST calculate endpoint — do not GET it.

Full REST contract: REST API docs.

Tool id: watts-to-volts
Engine: watts-to-volts
REST: POST /api/v1/calc/watts-to-volts
MCP: execute_calculation with capability_id: "electrical.watts_to_volts"
Agent input schema: Canonical (MCP / Agent)
Output schema: JSON Schema (latest)
Versioned input schema: Immutable pin (1.3.1)
Versioned output schema: Immutable pin (1.3.1)

Operations

Declared calculation modes for this capability.

w-v-a
w-v-r
v-w

References

Human-readable sources plus CVP reference evidence classes.

Sources

Derived identities

Watt’s law / power identity — Real power P = V × I × PF (1φ); P = √3 × V × I × PF (3φ L-L)
Resistive power identity — P = V²/R ⇒ V = √(P·R)

Reference evidence classes: O1 model · O2 expected_values · O2 numerical_behavior

Try with an agent

Inspect, then execute. Same engine as REST and the human calculator.

curl -sS -X POST 'https://www.calculatorx.com/mcp' \
  -H 'Content-Type: application/json' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: tools/call' \
  -H 'Mcp-Name: inspect_capability' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"inspect_capability","arguments":{"capability_id":"electrical.watts_to_volts"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'

curl -sS -X POST 'https://www.calculatorx.com/mcp' \
  -H 'Content-Type: application/json' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: tools/call' \
  -H 'Mcp-Name: execute_calculation' \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"execute_calculation","arguments":{"capability_id":"electrical.watts_to_volts","inputs":{"a":240,"b":2,"phase":"single","pf":1,"factor":1},"calculation_version":"1.3.1"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'

Pin calculation_version (1.3.1) when the result must stay reproducible.

Inspect the trust tier and required assurance level before execution. Full protocol notes: MCP docs.