Power Unit Converter

Convert between different power units like watts, horsepower, joules/hour...etc

Power measures the rate at which energy is transferred, converted, or used. From the watts rating on your light bulbs to the horsepower of your car engine, power helps us understand how quickly work can be done. Our converter handles electrical units (watts, kilowatts), mechanical units (horsepower), and thermal units (BTU/hour).

History & Background

The concept of power emerged during the Industrial Revolution when James Watt needed to compare his steam engines to horses. He coined 'horsepower' as a marketing term around 1782, estimating a horse could do 33,000 foot-pounds of work per minute. The watt was later named in his honor and became the SI unit of power.

How to Convert

Horsepower to Kilowatts
kW = hp × 0.7457

Multiply mechanical horsepower by 0.7457 to get kilowatts.

Example: 200 hp × 0.7457 = 149.14 kW

Kilowatts to Horsepower
hp = kW × 1.341

Multiply kilowatts by 1.341 to get mechanical horsepower.

Example: 100 kW × 1.341 = 134.1 hp

BTU/hour to Watts
watts = BTU/h × 0.293

Multiply BTU per hour by 0.293 to get watts.

Example: 10,000 BTU/h × 0.293 = 2,930 W

Watts to Joules/second
J/s = W × 1

Watts and joules per second are equivalent (1 W = 1 J/s).

Example: 500 W = 500 J/s

Real-World Examples

Car Engine

A typical modern car engine produces around 150-200 horsepower.

180 hp=134.2 kW
LED Light Bulb

An LED bulb producing the same light as a 60W incandescent uses only about 9 watts.

9 W=0.012 hp
Window Air Conditioner

A 12,000 BTU/hour window AC unit is common for cooling a single room.

12,000 BTU/h=3.52 kW
Nuclear Power Plant

A large nuclear reactor can produce about 1,000 megawatts of electrical power.

1,000 MW=1 GW
Human Body at Rest

A resting human body produces about 80-100 watts of heat energy.

100 W=341 BTU/h
Tesla Model S

A Tesla Model S Performance has a peak power output of about 670 horsepower.

670 hp=500 kW

Did You Know?

  • The Sun radiates 384.6 yottawatts (3.846 × 10²⁶ W) of power, while Earth receives only about 174 petawatts of that.
  • James Watt's original estimate of horsepower may have been deliberately inflated—modern studies suggest horses work at about 0.7 hp continuously.
  • The human brain consumes about 20 watts of power—less than a typical light bulb—yet performs incredibly complex computations.
  • A microwave oven typically uses 1,000-1,200 watts, but the actual cooking power (magnetron output) is only 600-900 watts.
  • The 'Back to the Future' DeLorean needed 1.21 gigawatts to time travel—equivalent to about 1.6 million horsepower or 500 lightning bolts.

Power conversion table

1 W = 3.412141285851795 Btu/h1 watts equals 3.412141285851795 Btu-hour1 * 3.412141285851795 = X Btu/h
1 W = 0.05686901819677783 Btu/min1 watts equals 0.05686901819677783 Btu-minute1 * 0.05686901819677783 = X Btu/min
1 W = 0.0009478169879134378 Btu/s1 watts equals 0.0009478169879134378 Btu-second1 * 0.0009478169879134378 = X Btu/s
1 W = 860.4206500956025 cal(th)/h1 watts equals 860.4206500956025 calories(th)-hour1 * 860.4206500956025 = X cal(th)/h
1 W = 14.340344168260039 cal(th)/min1 watts equals 14.340344168260039 calories(th)-minute1 * 14.340344168260039 = X cal(th)/min
1 W = 0.2390057361376673 cal(th)/s1 watts equals 0.2390057361376673 calories(th)-second1 * 0.2390057361376673 = X cal(th)/s
1 W = 44.25366199052972 ft lbf/min1 watts equals 44.25366199052972 foot pounds-force-minute1 * 44.25366199052972 = X ft lbf/min
1 W = 0.7375610331754953 ft lbf/s1 watts equals 0.7375610331754953 foot pounds-force-second1 * 0.7375610331754953 = X ft lbf/s
1 W = 1e-9 GW1 watts equals 1e-9 gigawatts1 * 1e-9 = X GW
1 W = 0.0013404825737265416 hp (electric)1 watts equals 0.0013404825737265416 horsepowers (electric)1 * 0.0013404825737265416 = X hp (electric)
1 W = 0.0013410220895950279 hp (international)1 watts equals 0.0013410220895950279 horsepowers (international)1 * 0.0013410220895950279 = X hp (international)
1 W = 0.0013404053117581694 hp (water)1 watts equals 0.0013404053117581694 horsepowers (water)1 * 0.0013404053117581694 = X hp (water)
1 W = 0.0013596215248753635 hp (metric)1 watts equals 0.0013596215248753635 horsepowers (metric)1 * 0.0013596215248753635 = X hp (metric)
1 W = 3600 J/h1 watts equals 3600 joules-hour1 * 3600 = X J/h
1 W = 60 J/min1 watts equals 60 joules-minute1 * 60 = X J/min
1 W = 1 J/s1 watts equals 1 joules-second1 * 1 = X J/s
1 W = 0.8604206500956023 kcal(th)/h1 watts equals 0.8604206500956023 kilocalories(th)-hour1 * 0.8604206500956023 = X kcal(th)/h
1 W = 0.014340344168260038 kcal(th)/min1 watts equals 0.014340344168260038 kilocalories(th)-minute1 * 0.014340344168260038 = X kcal(th)/min
1 W = 367.1071953010279 kgf m/h1 watts equals 367.1071953010279 kilogram-force meters-hour1 * 367.1071953010279 = X kgf m/h
1 W = 6.118303516800861 kgf m/min1 watts equals 6.118303516800861 kilogram-force meters-minute1 * 6.118303516800861 = X kgf m/min
1 W = 0.001 kW1 watts equals 0.001 kilowatts1 * 0.001 = X kW
1 W = 0.000001 MW1 watts equals 0.000001 megawatts1 * 0.000001 = X MW
1 W = 1e-12 TW1 watts equals 1e-12 terawatts1 * 1e-12 = X TW
1 W = 0.00028434512332474514 TR1 watts equals 0.00028434512332474514 ton of refrigeration1 * 0.00028434512332474514 = X TR
1 W = 1e-15 PW1 watts equals 1e-15 petawatts1 * 1e-15 = X PW

F.A.Q. - Frequently Asked Questions

Popular power Conversions

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