Convert power units — watts, kilowatts, horsepower, BTU/hr.
| Unit | Name | Value |
|---|---|---|
| kW | Kilowatt | 0.001 |
| MW | Megawatt | 0.000001 |
| hp | Horsepower (mech) | 0.0013410219 |
| BTU/hr | BTU/hr | 3.4121425 |
Formula: Horsepower = Watt × 0.001341
Multiply any watt value by 0.001341 to get horsepower.
Reverse: Watt = Horsepower × 745.7
Common watt values — factor: 1 W = 0.001341 hp
| Watt (W) | Horsepower (hp) | Context |
|---|---|---|
| 0.1 W | 0.0001341 hp | LED night light |
| 1 W | 0.001341 hp | Phone charger standby |
| 5 W | 0.006705 hp | USB charger |
| 10 W | 0.01341 hp | LED bulb |
| 60 W | 0.08046 hp | Old incandescent bulb |
| 100 W | 0.1341 hp | Laptop |
| 500 W | 0.6705 hp | Small microwave |
| 750 W | 1.006 hp | 1 hp motor |
| 1,000 W | 1.341 hp | 1 kW / electric kettle |
| 2,000 W | 2.682 hp | 2 kW fan heater |
| 5,000 W | 6.705 hp | 5 kW shower |
| 1e+04 W | 13.41 hp | 10 kW home system |
| 100,000 W | 134.1 hp | 100 kW EV charger |
| 1,000,000 W | 1,341 hp | 1 MW turbine |
| 1.000e+09 W | 1,341,000 hp | 1 GW plant |
W ÷ 745.7 = hp.
745.7 W = 1 hp. 1,000 W = 1.341 hp.
hp × 745.7 = W.
Calculates power dissipation, heat generation, and efficiency in watts.
Specifies lamp wattage for photometric calculations and energy comparisons.
Uses watts as the SI power unit in energy, work, and thermodynamics lessons.
Verifies device power ratings meet regulatory limits expressed in watts.
Measures server and rack power consumption in watts for cooling calculations.
Tracks appliance consumption in watts using smart plugs and energy monitors.
The watt (W) is the SI unit of power, defined as one joule per second. It was named after James Watt, the Scottish inventor whose improvements to the steam engine in the 1760s–1780s powered the Industrial Revolution. The unit was officially adopted by the Second Congress of the British Association for the Advancement of Science in 1882.
Watts define the power consumption of all electrical devices: a phone charger draws 5–20W, a laptop 30–65W, a microwave 800–1200W. Electrical utility systems worldwide are rated and billed based on watts and kilowatts.
Interesting fact: James Watt himself coined the term 'horsepower' to market his steam engines to mine owners — he defined it as the power needed to lift 33,000 pounds one foot in one minute. The watt was named in his honor a century after his death.
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.
Converting watt to horsepower 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 W = 0.006705 hp and 10 W = 0.01341 hp. Reverse: 1 hp = 745.7 W. Exact factor: 1 W = 0.001341 hp.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.