§ 01 / TOOL
Power Converter.
STATUS READYUNITS 7BASE WATT
> CONVERT
// FROM
=
// TO
74.569987
RESULT.
hp → kW
74.569987 kW.
100 hp = 74.569987 kW
§ 02 / ABOUT
How it works.
Power is the rate of energy use. The SI unit is the watt (W) — one joule per second. A 100 W bulb uses 100 joules of energy every second it’s on.
// THE KEY CONVERSIONS
- 1 hp (mechanical, US) = 745.6998 W
- 1 PS (metric, EU) = 735.5 W
- 1 BTU/h = 0.29307 W
- 1 W = 3.412 BTU/h
- 1 kW = 1.341 hp = 0.7375 PS×something
// USE IT FOR
- Cars — translating between US hp and European PS specs.
- HVAC — comparing AC and heat-pump BTU/h ratings to electric watts.
- Generators — sizing a unit for a power draw in mixed units.
- Appliances — quick sanity check between nameplate watts and energy use over time.
§ 03 / FAQ
Common questions.
How many watts in 1 horsepower?+
Mechanical (US) horsepower = 745.7 W. Metric horsepower (PS, used in European auto specs) = 735.5 W. The two are close but not identical, which is why a 100 hp US car spec and a 100 PS European spec describe slightly different power levels.
How are HVAC BTU/h ratings related to watts?+
1 W ≈ 3.412 BTU/h. So a 12,000 BTU/h air conditioner is moving about 3,517 W of heat — the same as a 1-ton AC unit (12,000 BTU/h is the historical definition of "1 ton of cooling").
What’s the difference between energy and power?+
Energy is total capacity (joules); power is the rate (joules per second = watts). A 1500 W heater running for 2 hours uses 3 kWh of energy. Same heater running for 1 hour uses 1.5 kWh. The wattage is fixed; the energy depends on time.
Why does my electric bill say kWh, not just watts?+
Because what you pay for is energy, not the rate. A high-power appliance running briefly can use less energy than a low-power one running constantly. The kWh = power × time. Your bill totals all the kWh used in the month.
§ 04 / TOOLS
Related calculators.
§ 05 / READING