HomeCalculatorsPhysicsWatts to Horsepower Converter
Physics calculator

Watts to Horsepower Converter

Convert power between watts and mechanical horsepower (1 hp = 745.6998715822702 W). Runs locally in your browser.

Instant result
Result
—

Enter values to calculate.

Inputs—
Mode—
Formula—
Trust summary CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance
Input interpretation
Enter values to calculate.
Result
—
Assurance
Engineering
Declared partition coverage
PASS · 2/2 declared partitions (watt-hp, invalid-domain) · Matrix
Known limitations
  • Mechanical horsepower
  • Core CVP does not include live graph, viewport, or pointer interaction.
Model
Watt ↔ mechanical horsepower.
Scope
Mechanical hp
Verification
Engine tested · Source checked · v1.0.0 · CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance· View Manifest · CVP overview · Specification
Versions
Calculation 1.0.0 · CVP protocol 1.0.0-proposed
CVP identity
1/1 property · digest 589ba875bc11
Legacy regression
3/3 tests · Production surface contract 4/4
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.
Supplemental domain review
Internal · Pass
Named expert review
Not performed
CVP suite
1/1 golden · 1/1 CVP boundary · 1/1 invalid · 1/1 property · 1/1 cross-interface · 1/1 CVP contract · Manifest
Sources
  • NIST handbook — horsepower
  • NIST SP 811 / mechanical horsepower — horsepower
Sources
Evidence
1 legacy golden · 1 legacy boundary · legacy regression suite · 1/1 oracle-backed golden · 1/1 invalid · Artifact integrity PASS · CalculatorX physics review
This calculator CURRENT · Public schema 1.0.0 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.

W → hphp = W / 745.6998715822702
hp → WW = hp · 745.6998715822702
iMechanical hp, not metric PS (≈735.5 W).

How to use

1

Choose W → hp or hp → W

Pick the conversion direction.

2

Enter the power value

Value must be greater than zero for a meaningful result.

3

Read the converted power

Uses 1 hp = 745.6998715822702 W (mechanical horsepower).

Example calculations

Common configurations with formula and result.

ϟ

1 hp

mechanical

1·745.699…
745.699… W

Watts to Horsepower converter specification

Version 1.0.0 · Engine tested · Supplemental domain review · Internal · 2026-08-09

Calculation status

Review policy · Evidence · Reviewed by CalculatorX physics review

Definition
Mechanical horsepower: 1 hp = 745.6998715822702 W.
What it calculates
Watt ↔ mechanical horsepower.
Inputs
  • mode w-hp|hp-w
  • value
Outputs
  • hp or W number
Formula
W=hp·745.6998715822702
Assumptions
  • Mechanical hp
Units
  • W, hp
Boundary conditions
  • value≤0 → VALUE_MUST_BE_POSITIVE
Example
1 hp → 745.6998715822702 W
Validation cases

1 published on this page · 3/3 tests · Production surface contract 4/4 · View evidence

  • hp-w value=1 → 745.6998715822702
Sources
  • NIST handbook — horsepower
    Supports: mechanical hp definition
  • NIST SP 811 / mechanical horsepower — horsepower
    Supports: 1 hp ≈ 745.7 W
Last reviewed
2026-08-09
Reviewed by
CalculatorX physics review
Calculation version
1.0.0

Background

Interpretation and common distinctions.

Convert Watt ↔ mechanical horsepower.

Supported and not supported

Supported — Bidirectional W↔hp · API units.power.watt_hp

Not supported — Metric PS, boiler hp, electrical hp

Agent / API notes

Capability id: units.power.watt_hp · tool id: watt-hp · pin 1.0.0.

Other calculators in this family: kWh ↔ Joule, Force F=ma .

E kWh ↔ Joule › F Force F=ma ›
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Frequently asked questions

Key distinctions behind the calculation.

Is this metric horsepower?

No — mechanical (imperial) horsepower. Metric PS is not supported in v1.