About this Power Converter
Power is the rate at which work is done. It is used to rate everything from light bulbs (Watts) to car engines (Horsepower). This calculator provides precise conversions between electrical and mechanical power units.
Who this calculator is for
- Drivers, EV shoppers, and mechanics comparing horsepower and kilowatt ratings across vehicle specs.
- DIYers, engineers, and equipment buyers sizing motors, generators, and appliances.
- Students learning the difference between watts, kilowatts, and horsepower in practical examples.
When to use it
- Use it when a motor, generator, or vehicle spec sheet switches between watts, kilowatts, and horsepower.
- Use it to compare electrical appliance ratings with mechanical output figures in tools or engines.
- Use it before estimating energy use, operating cost, or torque-related performance.
How to use this calculator
- Enter the Power value.
- Select the From unit (e.g., Horsepower).
- Select the To unit (e.g., Kilowatts).
- See the converted result immediately.
Key assumptions
- Conversions use fixed factors for watts, kilowatts, and mechanical horsepower.
- Horsepower here refers to mechanical horsepower rather than metric horsepower or boiler horsepower.
- The tool compares rated power values only and does not model efficiency losses, duty cycle, or torque curves.
Accuracy and testing
Review formula sources, default test cases, assumptions, unit handling, rounding rules, and changelog for this calculator.
How this calculator works
Conversions use standard factors:
* 1 Kilowatt (kW) = 1000 Watts
* 1 Mechanical Horsepower (hp) = 745.7 Watts
Inputs explained
Watt (W)
The SI unit of power. 1 Joule per second.
Horsepower (hp)
Mechanical horsepower (Imperial). The standard for cars in the US/UK.
Kilowatt (kW)
1000 Watts. Commonly used for electric motors and home appliances.
Understanding your results
Useful for comparing electric cars (kW) to gas cars (hp), or sizing generators for tools.
Example scenarios
Car Engine
Convert 300 HP to kW. Result: ~223.7 kW.
Light Bulb
Convert 60 W to kW. Result: 0.06 kW.
EV Motor
Convert 150 kW to HP. Result: ~201 HP.
Key Features
- Engine & Electrical Units
- High Precision
- Formula Display
Tips & Best Practices
- Electric Vehicles (EVs) often list power in kW. Multiply by ~1.34 to get Horsepower.
- Don't confuse Energy (kWh) with Power (kW). Power is how fast you use energy; Energy is the total amount used.
Glossary of Terms
- SI Unit
- The Watt (W) is the standard international unit for power.
- Mechanical Horsepower
- Based on James Watt's estimation of a horse's work rate (550 ft-lb/s).