Convert Power
Convert power measurements between different units quickly and accurately
Power Conversion Calculator
Popular Power Conversions
Quickly convert between the most commonly used power units.
Understanding Power Measurements
Power conversions are essential for various applications, from small electronics and IoT devices to massive power plants and industrial systems. Understanding power conversions across the full spectrum—from milliwatts to gigawatts—ensures accurate and consistent results in engineering, HVAC, energy management, and scientific applications.
Common Power Units
Small Scale Units
- Milliwatt (mW) - Electronics, IoT
- Watt (W) - Household appliances
- Kilowatt (kW) - Major appliances
Large Scale Units
- Megawatt (MW) - Industrial, wind turbines
- Gigawatt (GW) - Power plants, national grids
Mechanical Units
- Mechanical Horsepower (hp) - US/Imperial
- Metric Horsepower (PS) - European
- Foot-pound per Second (ft·lb/s)
HVAC & Industrial Units
- Tons of Refrigeration (TR) - Cooling systems
- Boiler Horsepower (BHP) - Steam boilers
- British Thermal Unit per Hour (BTU/h IT)
Common Applications
| Field | Typical Units | Common Range |
|---|---|---|
| Electronics & IoT | mW, W | 1mW - 100W |
| Household Appliances | W, kW | 10W - 5kW |
| Automotive | hp, kW | 100-500 hp |
| HVAC Systems | TR, BHP, kW | 2-1000 TR |
| Industrial Equipment | kW, MW, BHP | 10kW - 100MW |
| Power Plants | MW, GW | 100MW - 10GW |
| Renewable Energy | kW, MW, GW | 5kW - 5GW |
Conversion Tips
- Use a calculator for precise power conversions
- For quick estimates: 1 mechanical horsepower = 745.7 watts
- For quick estimates: 1 metric horsepower (PS) = 735.5 watts
- For HVAC: 1 ton of refrigeration = 12,000 BTU/hr (IT) = 3.517 kW
- For industrial: 1 boiler horsepower = 33,475 BTU/hr (IT) = 9.81 kW
- Remember: 1 kW = 1,000 W, 1 MW = 1,000 kW, 1 GW = 1,000 MW
- For electronics: 1,000 mW = 1 W
Power Conversions
| Conversion | Formula/Rule | Quick Answer |
|---|---|---|
| Milliwatts to Watts | 1 W = 1,000 mW | Divide mW by 1,000 |
| Watts to Kilowatts | 1 kW = 1,000 W | Divide W by 1,000 |
| Megawatts to Gigawatts | 1 GW = 1,000 MW | Divide MW by 1,000 |
| Watts to Mechanical Horsepower | 1 hp = 745.7 W | Divide W by 745.7 |
| Mechanical Horsepower to Watts | 1 W = 0.00134 hp | Multiply hp by 745.7 |
| Watts to Metric Horsepower | 1 PS = 735.5 W | Divide W by 735.5 |
| Metric Horsepower to Watts | 1 W = 0.00136 PS | Multiply PS by 735.5 |
| BTU/hr to Tons of Refrigeration | 1 TR = 12,000 BTU/hr (IT) | Divide BTU/hr by 12,000 |
| kW to Boiler Horsepower | 1 BHP = 9.81 kW | Divide kW by 9.81 |
| Watts to BTU/h | 1 BTU/h (IT) = 0.293 W | Divide W by 0.293 |
| BTU/h to Watts | 1 W = 3.412 BTU/h (IT) | Multiply BTU/h by 0.293 |
| Watts to Foot-pounds per Second | 1 ft·lb/s = 1.356 W | Divide W by 1.356 |
Our comprehensive power conversion tool covers the full spectrum from milliwatts to gigawatts, supporting electronics, HVAC, industrial, automotive, and energy applications. Whether you're designing IoT devices, sizing HVAC systems, or planning renewable energy projects, our converter provides accurate conversions for any power-related calculation.
Power Conversion Questions
Everything you need to know about power measurements and conversions
What's the difference between power and energy?
Power is the rate at which energy is used or transferred, measured in watts. Energy is the total amount of work done, measured in watt-hours or joules. Think of power as the speed of water flowing from a faucet, and energy as the total amount of water collected. A 100-watt bulb uses 100 watts of power, and if left on for 10 hours, it consumes 1,000 watt-hours (1 kWh) of energy.
How do I convert between horsepower and watts?
1 mechanical horsepower (hp) = 745.7 watts. 1 metric horsepower (PS, often used in Europe) = 735.5 watts. To convert hp to watts, multiply by 745.7. To convert watts to hp, divide by 745.7. For example, a 200 hp car engine produces about 149 kW of power.
What are tons of refrigeration (TR)?
One ton of refrigeration equals the cooling power needed to freeze one short ton (2,000 pounds) of water in 24 hours. 1 TR = 12,000 BTU/hr = 3.517 kW. This unit is commonly used for air conditioning and refrigeration systems. A typical home air conditioner might be rated at 2-5 tons (24,000-60,000 BTU/hr).
What is boiler horsepower (BHP)?
Boiler horsepower measures the power output of steam boilers. 1 BHP = 33,475 BTU/hr = 9.81 kW. It's based on the power needed to evaporate 34.5 pounds of water per hour at 212°F. This unit is used primarily in industrial steam applications and power plant boilers.
How much power does the average home use?
The average US home uses about 1.2 kW continuously (10,500 kWh per year ÷ 8,760 hours). Peak usage might reach 5-10 kW when multiple appliances run simultaneously. For comparison, this average power consumption is equivalent to about 1.6 horsepower running constantly.
What's the difference between mechanical and metric horsepower?
Mechanical horsepower (745.7 W) is used primarily in the US and UK, while metric horsepower or PS (735.5 W) is used in Europe and many other countries. The difference is about 1.4%. Car manufacturers often specify both: a 300 hp engine might also be rated as 304 PS or 221 kW.
How do I size a generator for my needs?
Add up the wattage of all devices you want to run simultaneously, then add 20-25% safety margin. Consider that motors and compressors need 2-3 times their running wattage to start. For example, if you need 3,000W continuously with occasional 5,000W startup surges, choose a 6,000W+ generator.
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