Verified calculation capability

Watts to kVA Calculation Capability

Convert real power in watts to apparent power in kVA using power factor: kVA = W ÷ (1000 × PF). Same PF rule as Watts to VA, scaled to kilovolt-amperes. · Electrical

Capability ID electrical.watts_to_kva · version 1.3.1

Open calculator REST API MCP Evidence Evidence JSON Review policy

Model

Watts → kVA

Watts → kVA: kVA = W ÷ (1000 × PF)
kVA → watts: W = kVA × 1000 × PF
From kilowatts: kVA = kW ÷ PF
Power factor: PF = W ÷ (kVA × 1000)

Inputs / Outputs

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

Symbol	Quantity	Unit	Role
`a`	Real power in W (w→kVA) or apparent power in kVA (kVA→W)	—	input
`b`	Power factor PF. Engine field name is b.	—	input
`factor`	0.001 for W→kVA; 1000 for kVA→W	—	input
`formula`	—	—	output
`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

PF between 0 and 1 (runtime treats missing/zero PF carefully on quotient)
No voltage/phase required

Example

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

2000 W, PF 0.8 → 2.5 kVA

Open this example in the calculator

Trust

Review-policy: engine tested — automated tests, sources, version lock, and evidence published. Supplemental to CVP; not Domain Expert Review. See CVP and Review policy.

Tier: Engine tested — catalog token engine_tested
Calculation version: 1.3.1
Evidence tests: 11/11 calculation tests · golden 11/11 · boundary 0/0 · property 0/0
Engine tested: Yes
Source checked: Yes
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)

Production attestation: Embedded snapshot: STALE · Last attested schema matched 1.3.1 snapshot / local build · Semantic contract ✓ · Last attestation PASS · current evidence changed · re-attestation required · Public/cache ✓ · Origin ✓ · Live production status PASS (0 stale; 164 CURRENT) @ 2026-09-16T06:44:24.909Z
Semantic contract: PASS
Evidence attested at: 2026-09-16T06:44:24.203Z
Last production check: 2026-09-16T06:44:24.203Z
Public / cache: PASS
Origin: PASS

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.

Tool id: watts-to-kva
Engine: scale-quotient
REST: POST /api/v1/calc/watts-to-kva
MCP: execute_calculation with capability_id: "electrical.watts_to_kva"
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-kva
kva-w

References

Human-readable sources plus CVP reference evidence classes.

Sources

Try with an agent

Inspect this capability via same-origin MCP, then call execute_calculation.

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_kva"}}}'

Inspect the trust tier and required assurance level before execution. Pin calculation_version (1.3.1) when reproducibility matters. Full protocol notes: MCP docs.