Convert power units — watts, kilowatts, horsepower, BTU/hr.
| Unit | Name | Value |
|---|---|---|
| W | Watt | 745.7 |
| kW | Kilowatt | 0.7457 |
| MW | Megawatt | 0.0007457 |
| BTU/hr | BTU/hr | 2544.4346 |
Formula: Kilowatt = Horsepower × 0.7457
Multiply any horsepower value by 0.7457 to get kilowatt.
Reverse: Horsepower = Kilowatt × 1.341
Common horsepower values — factor: 1 hp = 0.7457 kW
| Horsepower (hp) | Kilowatt (kW) | Context |
|---|---|---|
| 0.1 hp | 0.07457 kW | Small motor |
| 0.5 hp | 0.3729 kW | Half hp pump |
| 1 hp | 0.7457 kW | 1 hp motor |
| 5 hp | 3.729 kW | 5 hp outboard |
| 10 hp | 7.457 kW | 10 hp motor |
| 50 hp | 37.29 kW | Small car engine |
| 100 hp | 74.57 kW | Compact car |
| 150 hp | 111.9 kW | Mid-range car |
| 200 hp | 149.1 kW | Performance car |
| 300 hp | 223.7 kW | Sports car |
| 500 hp | 372.9 kW | Supercar |
| 1,000 hp | 745.7 kW | Race car |
| 1e+04 hp | 7,457 kW | Jet engine fraction |
| 100,000 hp | 7.457e+04 kW | Large ship engine |
| 1,000,000 hp | 745,700 kW | Power plant fraction |
hp × 0.7457 = kW. Round to × 0.746.
100 hp = 74.6 kW. 1 hp ≈ 0.75 kW.
kW × 1.341 = hp.
Rates car engine output in horsepower for marketing and performance comparison.
Specifies boat and ship engine power in horsepower for propulsion system design.
Rates pump motor size in horsepower for industrial and agricultural applications.
Sizes compressor motors in horsepower for commercial refrigeration systems.
Compares vehicle performance and evaluates engine modifications in horsepower.
Selects motors and compressors based on horsepower ratings in US specifications.
Horsepower (hp) was defined by James Watt in the 1780s to quantify steam engine output in terms familiar to mine operators who used horses to pump water. One mechanical horsepower equals 550 foot-pounds per second = 745.7 watts.
Horsepower remains the dominant power rating for vehicle engines in the United States, Canada, and the UK. Car engines range from 70 hp (economy) to 700+ hp (sports cars). Electrical motors, pumps, and industrial equipment are often rated in both kW and hp.
Interesting fact: There are multiple horsepower definitions: mechanical hp (745.7 W), metric hp (735.5 W), electrical hp (746 W), and boiler hp (9,810 W). Most automotive usage refers to mechanical hp. A racehorse at full gallop produces about 14–15 hp peak, not 1 hp.
The kilowatt (kW) equals 1,000 watts and is the practical power unit for household appliances, electric vehicles, and small engines. It became the standard billing unit for electricity with the growth of the electrical grid in the late 19th century.
Household power consumption is measured in kilowatts: a typical home draws 1–3 kW on average, peaking at 5–10 kW. Electric vehicle motors are rated in kW: a Tesla Model 3 delivers about 200–350 kW peak. Solar panel systems are sized in kilowatts.
Interesting fact: 1 kW = 1.341 horsepower. A Tour de France cyclist can sustain about 0.4 kW for hours; peak sprints reach 1.5–2 kW. The average human metabolic rate at rest is about 0.08 kW (80 watts).
Converting horsepower to kilowatt is common across electrical engineering, automotive, and HVAC industries. Different sectors use different power units — watts and kilowatts in electrical systems, horsepower in automotive and industrial machinery, and BTU/hr in heating and cooling — making accurate conversion essential for international equipment specifications and cross-disciplinary engineering.
Quick reference: 5 hp = 3.729 kW and 10 hp = 7.457 kW. Reverse: 1 kW = 1.341 hp. Exact factor: 1 hp = 0.7457 kW.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.