Convert Horsepower (electric) (hp(E)) to Watts (W)
1 horsepower (electric) equals 746 watts.
Horsepower (electric) to Watt Converter
What Is Electric Horsepower?
Electric horsepower (hp(E)) is a unit of power defined as exactly 746 watts (IEEE standard). It is used to rate electric motors, pumps, and compressors. Unlike mechanical or metric horsepower, the electric variant has a clean, exact definition.
What Is a Watt?
The watt (W) is the SI unit of power, defined as 1 joule per second. Common multiples include kilowatt (kW = 1,000 W) and megawatt (MW = 1,000,000 W). Watts measure the rate of energy use or production.
Electric Horsepower to Watts Formula
The conversion is exact:
watts = hp(E) × 746 exact
This is exact by IEEE definition. Note: mechanical hp ≈ 745.7 W and metric hp (PS/CV) ≈ 735.5 W — always specify which variant.
Worked Example
Convert a 5 hp electric motor to watts:
- Multiply: 5 × 746 = 3,730 W = 3.73 kW
Quick Estimation
Multiply hp by 750 for a quick approximation. 5 × 750 = 3,750 W (actual: 3,730 W — within 0.5%).
Common Use Cases
- Electric motor specifications: Pool pumps, HVAC compressors, and industrial motors are often rated in hp. Converting to watts helps compare with metric-rated equipment and size electrical circuits.
- Motor label comparison: Some motors show hp, others show kW. Knowing that 1 hp(E) = 0.746 kW helps compare instantly.
- Electrical circuit sizing: Electricians need watts to calculate current draw (amps = watts ÷ volts) for breaker sizing and wire gauge selection.
Frequently Asked Questions
How many watts are in 1 horsepower?
It depends on the type: electric hp = exactly 746 W, mechanical hp ≈ 745.7 W, metric hp (PS/CV) ≈ 735.5 W. This converter uses electric horsepower (746 W).
What is the difference between electric and mechanical horsepower?
Electric hp is defined as exactly 746 W (IEEE standard). Mechanical hp is defined as 550 ft·lbf/s ≈ 745.6999 W. The difference is less than 0.04%, but electric hp has the cleaner definition. Metric hp (PS/CV) = 75 kgf·m/s ≈ 735.499 W is about 1.4% less.
How many amps does a 1 hp motor draw?
At 120V: 1 hp = 746 W ÷ 120V ≈ 6.2 amps (ideal). Real motors draw more due to inefficiency and power factor — typically 8–10 amps for a 1 hp motor at 120V. At 240V, it is roughly half: 3–5 amps.
Why is electric horsepower exactly 746 watts?
The IEEE chose 746 W as a convenient round number close to the mechanical horsepower (745.7 W) for use with electric motors. It simplifies calculations while being practically equivalent to the mechanical definition.
Common Horsepower (electric) to Watt Conversions
| Horsepower (electric) | Watt | Actions |
|---|---|---|
| 12 horsepower (electric) | 373 watts | |
| 1 horsepower (electric) | 746 watts | |
| 2 horsepower (electric) | 1492 watts |
| Horsepower (electric) | Watt | Actions |
|---|---|---|
| 5 horsepower (electric) | 3730 watts | |
| 10 horsepower (electric) | 7460 watts |
Horsepower (electric) to watts Conversion Table
Reference table with common horsepower (electric) to watts conversions. All values calculated with high precision.
Horsepower (electric) to Watts Table
0.0001 to 12
Horsepower (electric) to Watts Table
1 to 100000
Watts to Horsepower (electric) Table
0.1 to 500
Watts to Horsepower (electric) Table
1000 to 1 × 108
Looking for the reverse? Convert Watt to Horsepower (electric)
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