Watts to HP Power Converter
Convert power ratings between watts, kilowatts, horsepower and BTU per hour. Compare motors, check EV charger specs, or size heaters and compressors.
Last updated: May 2026
Enter a value to see the conversion instantly.
How to use this power converter
Enter power in any unit and see the equivalent in all others. The quick buttons give you typical values: 100W is a small motor or bright LED bulb. 750W is about 1 horsepower. 2000W is a decent space heater. 7400W is roughly 10 HP for workshop machinery.
Common power reference values
| Application | Watts | kW | hp | BTU/hr |
|---|---|---|---|---|
| Laptop charger | 65-100 W | 0.065-0.1 kW | 0.09-0.13 hp | 222-341 BTU/hr |
| Home EV charger (Level 2) | 7400 W | 7.4 kW | 9.9 hp | 25,254 BTU/hr |
| Small workshop motor | 750 W | 0.75 kW | 1.0 hp | 2,559 BTU/hr |
| Space heater | 1500-2000 W | 1.5-2 kW | 2.0-2.7 hp | 5,118-6,824 BTU/hr |
| Window AC unit | 900-1500 W | 0.9-1.5 kW | 1.2-2.0 hp | 3,071-5,118 BTU/hr |
| Air compressor | 1500-3700 W | 1.5-3.7 kW | 2.0-5.0 hp | 5,118-12,626 BTU/hr |
| EV fast charger (DC) | 50,000 W | 50 kW | 67 hp | 170,602 BTU/hr |
When you need this tool
Your garage needs a 240V circuit for an air compressor but the label says 3 HP and your electrician asks how many watts. Or you're comparing portable AC units where one lists 12,000 BTU/hr and another shows 3.5 kW. Motor nameplates use HP in the US, kW in Europe, and watts everywhere else. Convert between them here so you size breakers correctly and compare specs fairly.
Frequently Asked Questions
When do I need to convert between watts and horsepower?
Motor and equipment nameplates use different power units by region and age. US equipment often shows HP, European equipment shows kW, and electrical systems always use watts. Electricians, mechanics and engineers need to convert to match equipment specs with breaker ratings or compare across brands.
What is the formula?
1 hp (mechanical) = 746 watts. 1 kW = 1000 watts. 1 BTU/hr ≈ 0.293 watts. These conversions let you translate a motor nameplate into the units your tools or circuits expect.
Why does this matter for circuit sizing?
A 3 HP motor is about 2.2 kW or 2200 watts. Size the circuit wrong (confuse HP with kW, for example) and the breaker trips or doesn't protect properly. Getting the conversion right prevents overloads and keeps equipment safe.