Convert Kilowatts to Horsepower - Power Converter
This converter translates power expressed in kilowatts (kW) into horsepower (hp). Kilowatts are the SI-derived unit for power, commonly used in engineering and regulation; horsepower remains widely used in automotive and machinery specifications.
There are multiple definitions of horsepower in common use (mechanical/imperial, metric/‘PS’, and electrical). This tool uses mechanical (imperial) horsepower as the default conversion basis. See methodology and examples below for alternative definitions and guidance on accuracy, rounding, and regulatory considerations.
Governance
Record 537f5a845ee1 • Reviewed by Fidamen Standards Committee
Interactive Converter
Convert between kilowatt and horsepower with precision rounding.
Quick reference table
| Kilowatt | Horsepower |
|---|---|
| 1 kW | 1.341 hp |
| 5 kW | 6.705 hp |
| 10 kW | 13.41 hp |
| 25 kW | 33.526 hp |
| 50 kW | 67.051 hp |
| 100 kW | 134.102 hp |
Methodology
Conversion is a fixed mathematical relationship that maps kilowatts (1 kW = 1000 watts) to a chosen horsepower definition expressed in watts. The converter applies the defined watt-per-horsepower constant to perform a direct unit conversion without estimation or empirical measurement.
Default choice: mechanical (imperial) horsepower where 1 hp = 745.699872 watts. Alternative commonly used definitions are metric horsepower (1 PS = 735.49875 W) and electrical horsepower (commonly quoted as 746 W). Use the appropriate definition for your domain or regulatory requirement.
Key takeaways
This converter performs exact arithmetic unit conversion from kilowatts to horsepower using a chosen watt-per-horsepower constant. Default is mechanical (imperial) horsepower = 745.699872 W.
Confirm which horsepower definition applies to your context, account for measurement uncertainty when converting empirical measurements, and follow relevant standards and regulations when publishing or labeling results.
Worked examples
100 kW → mechanical hp: (100 × 1000) / 745.699872 = 134.102209 hp (rounded to 6 decimal places)
50 kW → metric hp (PS): (50 × 1000) / 735.49875 = 67.981081 hp (PS)
1 kW → electrical hp: (1 × 1000) / 746 = 1.341005 hp (electrical convention)
F.A.Q.
Which horsepower definition does this converter use by default?
The default is mechanical (imperial) horsepower where 1 hp = 745.699872 W. The page_content includes formulas for metric horsepower (PS) and the common electrical horsepower convention (746 W). Choose the definition that matches your industry standard or regulation.
How accurate is the conversion?
The conversion uses exact constants as defined by standards organizations for watt and published horsepower definitions. Numerical rounding is application-dependent; report results to a precision that matches measurement uncertainty. For regulatory or lab work follow institutional precision rules (for example, significant digits from measurement devices or reporting standards).
If I measured power on a dynamometer, can I rely on this conversion for published horsepower?
Dynamometer readings are empirical and carry measurement uncertainty. Use this unit conversion to translate average power units, but account for instrument calibration, repeatability, and test standards (dynamometer test procedures and ambient condition corrections). When publishing official ratings, follow the applicable testing standard (industry or regional certification body).
Are there regulatory requirements about which unit to display?
Regulatory and labeling requirements differ by jurisdiction. Many countries require SI units (watts/kW) for official documentation; others still permit or require horsepower in consumer labeling. Refer to national and regional regulations for marking and reporting requirements.
Why do different sources show slightly different conversion factors?
Differences come from which horsepower definition is used and rounding conventions. Mechanical, metric (PS), and electrical horsepower are based on slightly different watt values. Always confirm which hp variant is intended before comparing numbers from different sources.
Sources & citations
- NIST - The International System of Units (SI) — https://www.nist.gov/pml/metric-si/si-units
- BIPM - The International System of Units (SI Brochure) — https://www.bipm.org/en/publications/si-brochure
- ISO - Quantities and units (ISO 80000 series overview) — https://www.iso.org/standard/64973.html
- IEEE Standards and Units Resources — https://standards.ieee.org/
- OSHA - Laws and Regulations — https://www.osha.gov/laws-regs
- NIST SP 811 — Guide for the Use of the International System of Units — https://www.nist.gov/pml/special-publication-811
Further resources
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
Record ID: 537f5a845ee1What changed (latest)
v1.0.0 • 2025-11-12 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Public QA status
PASS — golden 25 + edge 120
Last run: 2026-01-23 • Run: golden-edge-2026-01-23
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
What changed (latest)
v1.0.0 • 2025-11-12 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Public QA status
PASS — golden 25 + edge 120
Last run: 2026-01-23 • Run: golden-edge-2026-01-23
Engine
v1.0.0
Data
Baseline (no external datasets)
Content
v1.0.0
UI
v1.0.0
Governance
Last updated: Nov 12, 2025
Reviewed by: Fidamen Standards Committee (Review board)
Credentials: Internal QA
Risk level: low
Reviewer profile (entity)
Fidamen Standards Committee
Review board
Internal QA
Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person
Semantic versioning
- MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
- MINOR: New features or fields that do not change existing outputs for the same inputs.
- PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.
Review protocol
- Verify formulas and unit definitions against primary standards or datasets.
- Run golden-case regression suite and edge-case suite.
- Record reviewer sign-off with credentials and scope.
- Document assumptions, limitations, and jurisdiction applicability.
Assumptions & limitations
- Uses exact unit definitions from the Fidamen conversion library.
- Internal calculations use double precision; display rounding follows the unit's configured decimal places.
- Not a substitute for calibrated instruments in regulated contexts.
- Jurisdiction-specific rules may require official guidance.
Change log
v1.0.0 • 2025-11-12 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: b60844846fb6