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What does this converter do?
Horsepower to kW converter instantly converts hp to kilowatts and back, mechanical, metric or electrical. Free, private, runs locally in your browser.
- 1 mechanical hp = 0.7457 kilowatt · 1 kilowatt = 1.341 mechanical hp
- All conversions route through the watt as the base unit, so every pair of units agrees regardless of which two you enter.
- Standard factors are shown in the formula panel at the precision the calculator actually uses, so the arithmetic and the panel agree.
Reference factors (power)
Exact factors in terms of the watt, from NIST standards:
- 1 watt = 1 watt
- 1 mechanical hp = 745.7 watt
- 1 kilowatt = 1000 watt
How this calculator works
Formula
kilowatts = horsepower x 0.7457 (mechanical horsepower), and horsepower = kilowatts / 0.7457. Enter 1 in the Unit field for hp or 2 for kW. This is mechanical horsepower, not metric PS or electrical hp.
Worked example
1 mechanical hp = 0.7457 kilowatt · 1 kilowatt = 1.341 mechanical hp
Sources
Sources support the method, terminology, or planning context. Editable assumptions remain your responsibility.
Assumptions to verify
- Inputs are treated as exact decimal values.
- Standard (not historical or survey) unit definitions are used.
- The calculation uses the factors at the precision shown in the formula panel; rounding beyond that is display-only and adds no accuracy.
Frequently asked questions
Why convert through watt instead of directly?
Routing every unit through a single base (watt) means each unit needs only one exact factor against the standard, and any pair combines cleanly. Direct pair factors drift apart over time in hand-maintained tables; a base-unit graph cannot.
Where do these exact factors come from?
From published standards (NIST: SP 811 power conversions). Units like the inch are defined exactly (1 in = 2.54 cm since 1959), so conversions between standard units are exact, not approximate.
How precise is the converted power value?
The conversion applies the standard factors shown in the formula panel. The practical limit is your input: the result only regroups the number you entered, so digits beyond your original reading do not add accuracy. Note that 1 hp = 0.74569997 kW and metric PS differs from mechanical hp, so state which horsepower you mean when the figure matters.
Cite this tool
BoringToolsKit. “Horsepower to kW Converter.” boringtoolskit.com/horsepower-kw-converter/ (reviewed 2026-09-20). Free to reference in articles, syllabi, and answer posts with a link.
Privacy: Inputs and results stay in this browser. Conversion runs locally in your browser; review the output before relying on it.