Power Converter
Convert between power units including watts, kilowatts, horsepower, and BTU per hour.
W
All conversions from
Milliwatt
1000 mW
Kilowatt
0.001 kW
Megawatt
0.000001 MW
Gigawatt
1e-9 GW
Horsepower
0.0013410219 hp
Metric Horsepower
0.0013596216 PS
Electrical Horsepower
0.0013404826 hp(E)
Boiler Horsepower
0.000101942 hp(S)
BTU per Hour
3.4121416351 BTU/h
Ton of Refrigeration
0.0002843451 TR
Calorie per Second
0.2390057361 cal/s
Kilocalorie per Hour
0.8598452279 kcal/h
Foot-pound per Second
0.7375621493 ft·lbf/s
Erg per Second
10000000 erg/s
Frequently Asked Questions
To convert mechanical horsepower (hp) to watts, multiply by 745.7. For example, a 200 hp engine = 200 × 745.7 = 149,140 watts (about 149 kW). Note that metric horsepower (PS) equals 735.5 watts.
Watts (W) measure power—the rate of energy transfer. Watt-hours (Wh) measure energy—the total amount used over time. A 100W light bulb running for 10 hours uses 1,000 Wh (1 kWh) of energy.
Common appliances: LED bulb (10W), laptop (50W), refrigerator (100-400W), microwave (1,000-1,500W), hair dryer (1,000-1,800W), electric oven (2,000-5,000W), air conditioner (1,000-3,500W). Our converter helps compare power consumption across devices.
Mechanical (imperial) horsepower equals 745.7 watts, while metric horsepower (PS, CV, pk) equals 735.5 watts. James Watt defined horsepower based on how much a horse could lift, but different countries later adopted slightly different standards.