Power converter
Convert watts, kilowatts, horsepower, BTU/h and tons of refrigeration, the rates at which energy is delivered.
Converter
Quick pairs
tap to loadOne kilowatt in every power unit
19 rows| Unit | Symbol | 1 kW equals |
|---|---|---|
| Watt | W | 1,000 |
| Megawatt | MW | 0.001 |
| Gigawatt | GW | 1e-6 |
| Milliwatt | mW | 1,000,000 |
| Microwatt | µW | 1,000,000,000 |
| Horsepower (mechanical) | hp | 1.34102209 |
| Horsepower (metric) | PS | 1.359621617 |
| Horsepower (boiler) | hp(S) | 0.101941995 |
| Horsepower (electric) | hp(E) | 1.340482574 |
| BTU per hour | BTU/h | 3,412.141633 |
| BTU per minute | BTU/min | 56.86902722 |
| Ton of refrigeration | TR | 0.2843451361 |
| Calorie per second | cal/s | 239.0057361 |
| Kilocalorie per hour | kcal/h | 860.4206501 |
| Foot-pound per second | ft·lbf/s | 737.5621493 |
| Joule per second | J/s | 1,000 |
| Volt-ampere | VA | 1,000 |
| Kilovolt-ampere | kVA | 1 |
| Erg per second | erg/s | 1e10 |
Popular power conversions
1 pagesHow the kilowatt to horsepower (mechanical) conversion works
The watt, one joule per second, is the SI reference unit for power, and every unit here converts back to it. A kilowatt is 1,000 W, and horsepower comes in several distinct flavors that all converge on slightly different watt values: mechanical horsepower is 745.6998715822702 W, metric horsepower (PS) is 735.49875 W, and electrical horsepower is defined as exactly 746 W.
The default pairing is kilowatt to mechanical horsepower. Multiply by 1.34102209 to go from kilowatt to horsepower:
hp = kW × 1.34102209
Reverse it by multiplying by 0.7456998716, the same as dividing by 1.34102209. A 150 kW engine produces 150 × 1.34102209 = 201.15 hp. Worth noting: a car advertised at 200 PS (metric horsepower, common in European specs) is not 200 mechanical horsepower — it converts to roughly 147.1 kW, which is only about 197.3 mechanical hp, a gap of nearly 3 hp purely from using the wrong horsepower definition.
Power ratings split along industry and national lines more than almost any other unit on this site. Automotive marketing uses horsepower in the US, PS (metric horsepower) across much of Europe, and kilowatts in official EU vehicle documentation, often all three for the same car. Household appliances and electronics are rated in watts. HVAC and refrigeration equipment uses tons of refrigeration or BTU per hour. Industrial motors and power generation default to kilowatts and megawatts almost everywhere outside the US.
The trap worth flagging specifically is that “horsepower” is not one unit but at least four with meaningfully different sizes: mechanical (745.7 W), metric/PS (735.5 W), electrical (746 W), and boiler horsepower (9,809.5 W, used for rating steam boiler output and far larger than the others). A second, subtler issue is that volt-amperes (VA) and watts are not strictly interchangeable in AC electrical systems with a non-unity power factor — VA measures apparent power (voltage times current), while watts measure real power actually doing work, and the two only match exactly when the power factor is 1.
Questions
How many horsepower are in one kilowatt?
One kilowatt equals 1.34102209 hp (mechanical horsepower). The reverse figure, 1 hp = 0.7456998716 kW, is the one to use when converting a US horsepower spec into kilowatts for an EU datasheet.
Which units does this power converter cover?
20 units in total, referenced to the watt: the metric ladder (microwatt through gigawatt), four distinct horsepower definitions (mechanical, metric/PS, electrical, boiler), heat and refrigeration units (BTU per hour, BTU per minute, ton of refrigeration, calorie per second, kilocalorie per hour), and electrical/mechanical units (joule per second, volt-ampere, kilovolt-ampere, foot-pound per second, erg per second).
Why do I get slightly different numbers converting horsepower depending on the type?
Because mechanical, metric, and electrical horsepower are three separate historical definitions that happen to share a name. The differences are small in percentage terms (under 2%) but not zero, so always check which horsepower definition a spec sheet is using before treating the number as exact.
When would I use watts instead of horsepower or BTU per hour?
Watts and kilowatts are the universal default for electrical devices, motors, and most international engineering specs. Horsepower persists mainly in automotive and some industrial marketing, especially in the US. BTU per hour and tons of refrigeration are specific to heating and cooling equipment and rarely used outside HVAC.
Is a volt-ampere the same thing as a watt?
Only when the power factor is exactly 1. Volt-amperes measure apparent power in an AC circuit (voltage times current), while watts measure real power actually delivering work; in circuits with motors, transformers, or other inductive loads, the two values diverge, which is why electricians and electrical engineers track VA and watts separately.
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