Popular power conversions
- Watts to kilowatts1 W = 0.001 kW
- Watts to horsepower1 W = 0.00134102 hp
- Watts to BTU per hour1 W = 3.41214 BTU/h
- Watts to megawatts1 W = 0.000001 MW
- Kilowatts to watts1 kW = 1,000 W
- Kilowatts to horsepower1 kW = 1.34102 hp
- Kilowatts to BTU per hour1 kW = 3,412.14 BTU/h
- Kilowatts to megawatts1 kW = 0.001 MW
- Horsepower to watts1 hp = 745.7 W
- Horsepower to kilowatts1 hp = 0.7457 kW
- Horsepower to BTU per hour1 hp = 2,544.43 BTU/h
- Horsepower to megawatts1 hp = 0.0007457 MW
- BTU per hour to watts1 BTU/h = 0.293071 W
- BTU per hour to kilowatts1 BTU/h = 0.000293071 kW
- BTU per hour to horsepower1 BTU/h = 0.000393015 hp
- BTU per hour to megawatts1 BTU/h = 2.93071×10⁻⁷ MW
- Megawatts to watts1 MW = 1,000,000 W
- Megawatts to kilowatts1 MW = 1,000 kW
- Megawatts to horsepower1 MW = 1,341.02 hp
- Megawatts to BTU per hour1 MW = 3,412,140 BTU/h
- Metric horsepower to kilowatts1 PS = 0.735499 kW
- Kilowatts to metric horsepower1 kW = 1.35962 PS
- Tons of refrigeration to kilowatts1 TR = 3.51685 kW
- Kilowatts to tons of refrigeration1 kW = 0.284345 TR
- Tons of refrigeration to BTU per hour1 TR = 12,000 BTU/h
- BTU per hour to tons of refrigeration1 BTU/h = 0.0000833333 TR
About power units
Power is the rate of using or delivering energy: one watt is one joule per second. Engines are rated in horsepower or kilowatts, heating and cooling systems in BTU per hour or tons of refrigeration. Note that there are several horsepowers — mechanical (≈745.7 W), metric/PS (735.49875 W) and electrical (746 W).
Power unit reference
| Unit | Symbol | Value in W | System |
|---|---|---|---|
| Watt | W | 1 W | SI |
| Milliwatt | mW | 0.001 W | SI |
| Kilowatt | kW | 1,000 W | SI |
| Megawatt | MW | 1,000,000 W | SI |
| Gigawatt | GW | 1,000,000,000 W | SI |
| Horsepower (mechanical) | hp | 745.69987 W | US customary |
| Metric horsepower | PS | 735.49875 W | Metric |
| Electrical horsepower | hp(E) | 746 W | US customary |
| BTU per hour | BTU/h | 0.29307107 W | US customary |
| Ton of refrigeration | TR | 3,516.8528 W | US customary |
| Foot-pound per second | ft⋅lbf/s | 1.3558179 W | US customary |
| Calorie per second | cal/s | 4.184 W | Other |
| Kilocalorie per hour | kcal/h | 1.1622222 W | Other |
| Erg per second | erg/s | 1×10⁻⁷ W | CGS |
Frequently asked questions
What is the SI unit of power?
This converter uses the watt (W) as its reference unit; every other unit is defined relative to it.
How many power units can I convert?
14 units are supported here, across SI, US customary, Metric, Other, CGS systems. Every pair can be converted in both directions.
Does this power converter work offline?
Yes. Once the page has loaded, every calculation runs locally in your browser — nothing is sent to a server.