Power Unit Converter
Full Reference Table
Enter a value above and click Convert to populate the table.
| Unit | Value |
|---|
Power Unit Conversion Guide
Power is the rate at which energy is transferred or work is done. Different industries use different power units — electrical engineers use watts and kilowatts, mechanical engineers often use horsepower, and HVAC professionals use BTU/hour. Our free power converter handles all the major units with instant results.
Watts and Kilowatts — Electrical Power
The watt (W) is the SI unit of power, defined as one joule per second. It is the standard unit for electrical appliances, light bulbs, solar panels, and grid electricity. Common multiples include the kilowatt (kW = 1,000 W) and the megawatt (MW = 1,000,000 W). Your household electricity bill charges in kilowatt-hours (energy = power × time).
Typical power consumption: a smartphone charger uses 5–20 W; a microwave uses 700–1,200 W (0.7–1.2 kW); a large home air conditioner uses 3–5 kW; a power plant generates hundreds of megawatts.
Horsepower — Mechanical Power
Horsepower (hp) was defined by James Watt in the 18th century to compare steam engine output to the power of draft horses. One mechanical horsepower equals exactly 550 foot-pounds per second, or approximately 745.7 watts. Car engines are rated in horsepower or kilowatts depending on the country. A typical family car has 100–200 hp (75–150 kW).
Note: there are several different definitions of horsepower. This converter uses the mechanical (imperial) horsepower of 745.69987 W, which is the most common in automotive contexts.
BTU/Hour — Heating and Cooling
The British Thermal Unit per hour (BTU/h) is the standard power unit for HVAC systems in the US and UK. Air conditioner capacity is typically stated in BTU/h. One BTU/h ≈ 0.2931 watts. A 12,000 BTU/h air conditioner uses about 3,516 watts (3.5 kW) at maximum capacity.
Megawatts — Grid-Scale Power
Megawatts measure the output of large power generators. A small wind turbine might produce 2–3 MW; a typical nuclear reactor generates 1,000–1,600 MW. Entire cities can run on hundreds of megawatts of generating capacity.