Power Converter
Convert power between watts, kilowatts, mechanical horsepower and megawatts, with the 745.7 watt horsepower definition and examples for engines and appliances.
Results
Result
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Educational estimates · not financial advice · free, no signup
Formula / how it works
1 kW = 1,000 W. 1 MW = 1,000 kW. 1 mechanical horsepower ≈ 745.7 W = 0.7457 kW. Therefore kW × 1.341 ≈ hp.
Detailed guide
What it is, how to use it, how to read the numbers, common mistakes, a worked example, formulas, and FAQs.
What this calculator is
Power is the rate of doing work or using energy. Electrical appliances are rated in watts and kilowatts, large installations in megawatts, and engines in horsepower in many countries. This converter changes a value between watts, kilowatts, horsepower and megawatts. Horsepower has several definitions. This tool uses the mechanical horsepower of about 745.7 watts. Metric horsepower is about 735.5 watts, a difference of around 1.4%, which matters when comparing figures from different markets. Power is not energy: a kilowatt is a rate, while a kilowatt-hour is an amount.
When to use / who it helps
- You are comparing a car engine's horsepower with a motor in kilowatts.
- You are sizing a generator or electric motor.
- You are reading a specification sheet that uses a different unit.
- You want to convert a power station rating to megawatts.
- You are checking an appliance's rating.
How to use
Steps
- Enter the value.
- Choose the unit you are converting from.
- Choose the unit to convert to.
- Read the result.
- Check whether a figure is mechanical or metric horsepower.
- Remember that kWh is energy, not power.
How to interpret results
- 1 hp is a little less than 0.75 kW.
- 100 kW is about 134.1 hp.
- Megawatts are a thousand kilowatts.
- Ratings are maximum or rated values, not typical use.
- Metric and mechanical horsepower differ slightly.
Common mistakes & gotchas
- Confusing power (kW) with energy (kWh).
- Mixing mechanical and metric horsepower.
- Assuming engine power equals power at the wheels.
- Entering the wrong unit.
- Rounding too aggressively on large systems.
Worked example
Worked example — 1 hp and 100 kW
- 1 hp × 745.7 = 745.7 W = 0.7457 kW.
- 100 kW ÷ 0.7457 ≈ 134.1 hp.
- 2.5 MW × 1,000 = 2,500 kW.
- A 1,500 W heater is 1.5 kW, or about 2.0 hp.
Result: 1 hp equals 0.7457 kW, and 100 kW is about 134.1 hp.
To load the form's own demo values, tap Try example above the Calculate button.
How to calculate / formula
1 kW = 1,000 W. 1 MW = 1,000 kW. 1 mechanical horsepower ≈ 745.7 W = 0.7457 kW. Therefore kW × 1.341 ≈ hp.
Frequently asked questions
How many watts are in a horsepower?
About 745.7 for mechanical horsepower.
What is the difference between a kilowatt and a kilowatt-hour?
A kilowatt measures power; a kilowatt-hour measures the energy used over time.
What is metric horsepower?
About 735.5 watts.
How many kW is 1 MW?
1,000 kW.
Is engine horsepower the same as wheel horsepower?
No. Drivetrain losses reduce power at the wheels.
Does this convert electrical horsepower?
Only the mechanical definition is used here.