kW to HP Converter
Use this kW to HP converter to quickly convert kilowatts to horsepower and back. Includes formulas, examples and engineering-grade reference values.
Full original guide (expanded)
kW to HP Converter
Convert kilowatts (kW) to mechanical horsepower (HP) and back, using standard engineering conversion factors.
Power converter – kilowatts <→ horsepower
Mechanical horsepower: 1 HP = 745.699872 W. Metric horsepower (PS): 1 PS = 735.49875 W.
How to convert kW to HP
Power in kilowatts can be expressed in horsepower by applying a constant conversion factor that depends on the horsepower definition. This tool supports both mechanical horsepower and metric horsepower (PS).
Mechanical horsepower
1 HPmech = 745.699872 W
1 kW = 1000 W
HPmech = kW × 1000 / 745.699872 ≈ kW × 1.34102
kW = HPmech × 745.699872 / 1000 ≈ HP × 0.74570
Metric horsepower (PS)
1 PS = 735.49875 W
HPmetric = kW × 1000 / 735.49875 ≈ kW × 1.35962
kW = HPmetric × 735.49875 / 1000 ≈ HP × 0.73550
Example: 5 kW to HP
Using mechanical horsepower:
HP = 5 × 1000 / 745.699872 ≈ 6.71 HP
Engineering use cases
- Motor and pump sizing for HVAC and industrial equipment.
- Estimating engine horsepower from rated electrical power.
- Comparing European (kW) and US (HP) specifications on datasheets.
FAQ
Is 1 kW equal to 1.34 HP?
Yes, for mechanical horsepower the commonly used rounded factor is 1 kW ≈ 1.341 HP. The calculator uses the more precise constant 745.699872 W per HP internally.
Which horsepower should I use for cars?
In most English-language documentation and in North America, mechanical horsepower is used. In some European countries, metric horsepower (PS) still appears in legacy documentation.
Can I convert HP to kW with this tool?
Yes. Change the direction to “HP → kW” or press the swap button and enter the horsepower value. The result is shown immediately with the selected horsepower definition.
Formula (LaTeX) + variables + units
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Mechanical horsepower 1 HPmech = 745.699872 W 1 kW = 1000 W HPmech = kW × 1000 / 745.699872 ≈ kW × 1.34102 kW = HPmech × 745.699872 / 1000 ≈ HP × 0.74570
Metric horsepower (PS) 1 PS = 735.49875 W HPmetric = kW × 1000 / 735.49875 ≈ kW × 1.35962 kW = HPmetric × 735.49875 / 1000 ≈ HP × 0.73550
- No variables provided in audit spec.
- NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures - NIST — SI units — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/owm/metric-si/si-units
Last code update: 2026-01-19
- Initial audit spec draft generated from HTML extraction (review required).
- Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
- Confirm sources are authoritative and relevant to the calculator methodology.