How to Convert Kilowatts
To Horsepower, BTU/hr, and More
Get the FormulasA 10 kW electric motor, a 13.4 hp engine, and a 34,100 BTU/hr heater all produce the same power. Converting between these units is essential for comparing equipment, sizing systems, and understanding specifications across different industries.
Step-by-Step Conversions
Kilowatts to Horsepower
- Find your power in kilowatts (e.g., 75 kW)
- Multiply by 1.341
- Result: 75 × 1.341 = 100.6 hp
Horsepower to Kilowatts
- Find your power in horsepower (e.g., 200 hp)
- Divide by 1.341 (or multiply by 0.746)
- Result: 200 ÷ 1.341 = 149.2 kW
Kilowatts to BTU/hour
- Find your power in kilowatts (e.g., 5 kW)
- Multiply by 3,412
- Result: 5 × 3,412 = 17,060 BTU/hr
Comprehensive Conversion Table
| kW | Watts | hp (mech) | PS (metric) | BTU/hr |
|---|---|---|---|---|
| 0.5 | 500 | 0.67 | 0.68 | 1,706 |
| 1 | 1,000 | 1.34 | 1.36 | 3,412 |
| 2 | 2,000 | 2.68 | 2.72 | 6,824 |
| 5 | 5,000 | 6.71 | 6.80 | 17,060 |
| 10 | 10,000 | 13.41 | 13.60 | 34,120 |
| 25 | 25,000 | 33.53 | 33.99 | 85,300 |
| 50 | 50,000 | 67.05 | 67.98 | 170,600 |
| 100 | 100,000 | 134.10 | 135.96 | 341,200 |
Common Applications
Electric Motors
Motors often list both kW and hp:
| Motor Size | kW | hp |
|---|---|---|
| Small pump | 0.37 | 0.5 |
| Fan motor | 0.75 | 1 |
| Industrial pump | 7.5 | 10 |
| Compressor | 22 | 30 |
| Large industrial | 75 | 100 |
HVAC Systems
Heating/cooling capacity often uses BTU/hr or tons:
- 1 ton of cooling = 12,000 BTU/hr = 3.52 kW
- Residential AC: 2-5 tons (7-17.5 kW)
- Space heater: 1-2 kW (3,400-6,800 BTU/hr)
Power vs Energy
Don't confuse power (kW) with energy (kWh):
- Power (kW): Rate of energy use
- Energy (kWh): Total energy consumed over time
Energy = Power × Time
Example: A 2 kW heater running for 3 hours uses 6 kWh of energy.
Electricity Cost
Utility bills charge for energy (kWh), not power (kW). A 1 kW device costs the same per hour whether it's a 1 kW heater or ten 100W bulbs.
Regional Variations
| Region | Power Unit | Application |
|---|---|---|
| US/UK | hp (mechanical) | Vehicles, motors |
| Europe | kW, PS | Vehicles, appliances |
| Japan | kW, PS | Mixed usage |
| HVAC (US) | BTU/hr, tons | Heating/cooling |
| HVAC (intl) | kW | Heating/cooling |
| Scientific | W, kW | All applications |
Conclusion
Converting kilowatts requires different factors for different target units: ×1.341 for horsepower, ×1.360 for metric horsepower (PS), and ×3,412 for BTU/hour. The kilowatt is the universal scientific unit, while horsepower dominates automotive applications and BTU/hour is standard for HVAC in the US. Understanding these conversions helps compare equipment across different specification systems.