1 W in every unit
Values update with the converter above. Select a row to open that conversion's detailed page.
- Ton of Refrigeration0.0002843451 TR
- Kilowatt0.001 kW
- Megawatt0.000001 MW
- Metric Horsepower0.001359622 hp
- Mechanical Horsepower0.001341022 HP
- BTU per hour3.412142 BTU/h
Popular conversions
6 pairsKilowatt ↔ Watt
kW ↔ W
Kilowatt ↔ Metric Horsepower
kW ↔ hp
Megawatt ↔ Kilowatt
MW ↔ kW
Mechanical Horsepower ↔ Metric Horsepower
HP ↔ hp
Ton of Refrigeration ↔ Kilowatt
TR ↔ kW
BTU per hour ↔ Watt
BTU/h ↔ W
Unit guides
7 unitsDetailed guide to this category
Power measures the rate at which energy is transferred or used, distinct from energy itself (see the separate Energy category).
This category groups practical power conversions for engines, electrical equipment and generation capacity.
- Physical quantity
- Power
- SI unit
- Watt
- SI symbol
- W
- Common non-SI unit
- Horsepower
- Typical use
- Engine and equipment power rating
What is power?
Power is the rate at which energy is transferred or converted, expressed as energy per unit of time.
It is used to rate engines, motors, generators, electrical devices and power plants.
Watts, kilowatts, megawatts and horsepower
The watt is the SI unit of power. Kilowatts and megawatts scale it up for equipment and power plant capacity.
Horsepower is a traditional non-SI unit still common in the automotive industry; metric horsepower (PS/CV) and mechanical horsepower (HP) differ slightly in value.
Power versus energy
Power is a rate, while energy is an accumulated quantity. A device rated in watts describes how quickly it uses or delivers energy; energy bills and battery capacities are commonly expressed in kilowatt-hours.
For example, the same appliance can use different total energy amounts depending on how long it runs, even though its power rating stays the same.
Power units in equipment ratings
Watts and kilowatts are common for electrical appliances, motors and solar equipment. Horsepower remains common for vehicle engines, pumps and some mechanical equipment.
Cooling equipment may use tons of refrigeration, while heating and HVAC specifications can use BTU per hour. Check whether a specification means electrical input power, mechanical output power or thermal capacity before comparing equipment.
Unit comparison table
| Unit | Symbol | SI equivalent | System | Common use |
|---|---|---|---|---|
| Watt | W | 1 W = 1 J/s | SI derived unit | Appliance and electronic power ratings |
| Kilowatt | kW | 1 kW = 1,000 W | SI prefix | Motors, heating and solar equipment |
| Megawatt | MW | 1 MW = 1,000,000 W | SI prefix | Power plants and utility-scale generation |
| Mechanical Horsepower | hp | ≈ 745.7 W | Customary power unit | Engines and mechanical equipment |
| Ton of Refrigeration | TR | ≈ 3,516.85 W | HVAC capacity unit | Air-conditioning and refrigeration |
| BTU per Hour | BTU/h | ≈ 0.293071 W | Thermal power unit | Heating and HVAC specifications |
Units
| Unit | Symbol | Information |
|---|---|---|
| Watt | W | View unit guide |
| Kilowatt | kW | View unit guide |
| Metric Horsepower (PS) | hp | View unit guide |
| Megawatt | MW | View unit guide |
| Horsepower (Mechanical) | HP | View unit guide |
| Ton of Refrigeration | TR | View unit guide |
| BTU per hour | BTU/h | View unit guide |