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: BTU/hr = Horsepower × 2544
Multiply any horsepower value by 2544 to get btu/hr.
Reverse: Horsepower = BTU/hr × 0.000393
Common horsepower values — factor: 1 hp = 2544 BTU/hr
| Horsepower (hp) | BTU/hr (BTU/hr) | Context |
|---|---|---|
| 0.1 hp | 254.4 BTU/hr | Small motor |
| 0.5 hp | 1,272 BTU/hr | Half hp pump |
| 1 hp | 2,544 BTU/hr | 1 hp motor |
| 5 hp | 1.272e+04 BTU/hr | 5 hp outboard |
| 10 hp | 2.544e+04 BTU/hr | 10 hp motor |
| 50 hp | 127,200 BTU/hr | Small car engine |
| 100 hp | 254,400 BTU/hr | Compact car |
| 150 hp | 381,700 BTU/hr | Mid-range car |
| 200 hp | 508,900 BTU/hr | Performance car |
| 300 hp | 763,300 BTU/hr | Sports car |
| 500 hp | 1,272,000 BTU/hr | Supercar |
| 1,000 hp | 2,544,000 BTU/hr | Race car |
| 1e+04 hp | 25,440,000 BTU/hr | Jet engine fraction |
| 100,000 hp | 254,400,000 BTU/hr | Large ship engine |
| 1,000,000 hp | 2.544e+09 BTU/hr | Power plant fraction |
1 hp = 2544 BTU/hr. Memorize for instant estimates.
Use 2544 as a quick mental multiplier.
Multiply result by 0.000393 to recover the original hp value.
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.
BTU/hr (British Thermal Units per hour) is the Imperial unit of power used in heating, ventilation, and air conditioning (HVAC). One BTU is the heat needed to raise 1 pound of water by 1°F; divided by an hour gives a power rate equal to 0.293071 watts.
HVAC equipment is universally rated in BTU/hr in the United States: window air conditioners range from 5,000 to 25,000 BTU/hr; central AC systems from 18,000 to 60,000 BTU/hr. Natural gas furnaces are rated in BTU/hr output.
Interesting fact: 12,000 BTU/hr = 1 'ton of refrigeration' — the cooling power needed to melt one ton of ice in 24 hours. This legacy unit still defines residential AC capacity in the US, where a 'one-ton' unit is a 12,000 BTU/hr air conditioner.
Converting horsepower to btu/hr 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 = 1.272e+04 BTU/hr and 10 hp = 2.544e+04 BTU/hr. Reverse: 1 BTU/hr = 0.000393 hp. Exact factor: 1 hp = 2544 BTU/hr.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.