Why Convert Watts to Horsepower?
Converting between watts (W) and horsepower (hp) is one of the most common power conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert W to hp saves time and prevents errors.
Power conversions between W and hp are essential for automotive, electrical, and HVAC applications. Car specifications in Europe and China list engine power in kilowatts (kW), while the US and Japan prefer horsepower (hp). Home appliance energy labels show wattage for comparing electricity consumption. When sizing generators, air conditioners, or solar panels, accurate power conversion ensures you select the right equipment for your needs.
How to Convert Watts to Horsepower
To convert watts to horsepower, use the following formula:
hp = W × 0.00134102209
Example: 1 W = 0.00134102209 hp
For example, 5 W = 0.006705110448 hp, 10 W = 0.0134102209 hp, and 100 W = 0.134102209 hp. Our calculator above performs this conversion instantly with full precision — no rounding errors.
Common Use Cases
- Exactly one mechanical horsepower: 746 W = 1.000402479 hp
- A microwave oven at full power: 1000 W = 1.34102209 hp
- An electric kettle: 2000 W = 2.682044179 hp
- A professional cyclist's sustained output: 100 W = 0.134102209 hp
Common Mistakes to Avoid
- Horsepower variants: Mechanical horsepower (550 ft·lbf/s) ≈ 745.7 W, while metric horsepower (PS) ≈ 735.5 W. This converter uses mechanical hp.
- Peak vs continuous power: Motor specifications may list peak or continuous power. A "2000W peak" motor might only sustain 1200W continuously.
- Electrical vs mechanical: Electrical power (watts) and mechanical output (horsepower) differ by motor efficiency (typically 80-95%).
Pro Tips
- Memorize the factor: 1 W = 0.00134102209 hp. For quick mental math, remember this base conversion.
- Quick reference: 5 W = 0.006705110448 hp · 10 W = 0.0134102209 hp · 25 W = 0.03352555224 hp · 50 W = 0.06705110448 hp · 100 W = 0.134102209 hp
- Bookmark this page: Save this converter for instant access. It works offline once loaded — no internet needed.
Watts to Horsepower Conversion Table
| W | hp |
|---|---|
| 0.01 W | 0.0000134102209 hp |
| 0.1 W | 0.000134102209 hp |
| 0.5 W | 0.0006705110448 hp |
| 1 W | 0.00134102209 hp |
| 2 W | 0.002682044179 hp |
| 5 W | 0.006705110448 hp |
| 10 W | 0.0134102209 hp |
| 20 W | 0.02682044179 hp |
| 50 W | 0.06705110448 hp |
| 100 W | 0.134102209 hp |
| 500 W | 0.6705110448 hp |
| 1000 W | 1.34102209 hp |
All values in this table are mathematically exact per NIST SP 811.