How to convert horsepower to kilowatts
kW = x × 0.74569987158227
The input is mechanical horsepower. Engine output ratings can also depend on test conditions; unit conversion alone does not compare those conditions.
Worked example
kW = 100 × 0.74569987158227
100 hp = 74.569987 kW.
Conversion table in both directions
Values are generated by the same engine as the interactive converter.
| Input | hp → kW | kW → hp |
|---|---|---|
| 1 | 0.7457 | 1.341022 |
| 5 | 3.728499 | 6.70511 |
| 10 | 7.456999 | 13.410221 |
| 25 | 18.642497 | 33.525552 |
| 50 | 37.284994 | 67.051104 |
| 100 | 74.569987 | 134.102209 |
Unit definitions and sources
Mechanical horsepower differs from metric horsepower (PS). BTU per hour uses International Table BTU; a ton of refrigeration is exactly 12,000 BTU/h. dBm and dBW are logarithmic levels relative to 1 mW and 1 W, so they require a power greater than zero.
| Unit and system | Use | Definition | Relationship |
|---|---|---|---|
| Kilowatt (kW); si | Common units | Kilowatt measures power. w = (value in kW) × 1000. Common use: Rate of energy transfer. | Exact definition; numerical display may be rounded |
| Horsepower (mechanical) (hp); us | Common units | Horsepower (mechanical) measures power. w = (value in hp) × 745.6998715822702. Common use: Rate of energy transfer. | Exact definition; numerical display may be rounded |
Sources: BIPM: International System of Units; NIST: SP 811 Appendix B.8: conversion factors; ITU: ITU-R V.574: Use of the decibel and the neper in telecommunications; NIST: SP 811 Chapter 8: logarithmic quantities and units; BIPM: SI prefixes
Precision of power conversions
These 2 power units convert through Watt (W). 2 have an exact defined relationship to the base unit and 0 are conventional or measured values. Results and the tables on this page come from the same engine, so a table value can be checked against the converter directly.
Standard display shows up to six decimal places, switching to scientific notation for very large or small values. Calculation uses JavaScript binary floating point independently of display rounding, so extra digits are not a claim about measurement accuracy. Each unit lists its own source; a citation records where the definition comes from, not an independent review. See Conversion methodology for the review and correction process.