Power is energy per unit time. Cars are rated in horsepower or kilowatts, air conditioners in BTU per hour or tons of refrigeration, and light bulbs in watts. Note that mechanical horsepower (745.7 W) and metric horsepower (PS, 735.5 W) are different.
How to use the Power Converter
- Pick the unit you are starting from in the From menu and type your value.
- Pick the unit you want in the To menu. The heading changes to match – for example “Kilowatts to Watts Converter”.
- The most common power units are shown below at the same time, so you can compare them at a glance.
- Type into any result to convert backwards, then use Copy results – the copied text starts with the heading for your chosen units.
Results update as you type. Everything is calculated in your browser.
How it works
Every power unit is defined by an exact factor relative to the watt (the base unit). The calculator first turns the value you type into watts, then turns that into the unit you picked in the “To” menu and into each of the common units below it. This two-step method means any unit can be converted to any other – 11 units are available in each menu – and you can type into any field, including a result, to work in the other direction. Changing a unit menu keeps the quantity the same and just re-expresses it, and the page heading and copied results follow your choice.
How to convert power units
- Choose the unit you have in the From menu and type the value, for example 1 kW.
- Choose the unit you want in the To menu, for example watts. The page heading changes to “Kilowatts to Watts Converter”.
- The calculator multiplies by the watt factor of the “from” unit and divides by the factor of the “to” unit: 1 kW × 1,000 ÷ 1 = 1,000 W.
1 kilowatt in common units
| Unit | Value |
|---|---|
| Watts (W) | 1,000 |
| Milliwatts (mW) | 1,000,000 |
| Megawatts (MW) | 0.001 |
| Mechanical horsepower (hp) | 1.3410221 |
| Metric horsepower (PS) | 1.3596216 |
| BTU per hour (BTU/h) | 3,412.1416 |
| Kilocalories per hour (kcal/h) | 860.42065 |
| Tons of refrigeration (TR) | 0.28434514 |
Kilowatts conversion table
| Kilowatts | W | mW | MW | hp |
|---|---|---|---|---|
| 0.1 | 100 | 100,000 | 0.0001 | 0.13410221 |
| 0.5 | 500 | 500,000 | 0.0005 | 0.67051104 |
| 1 | 1,000 | 1,000,000 | 0.001 | 1.3410221 |
| 1.5 | 1,500 | 1,500,000 | 0.0015 | 2.0115331 |
| 2 | 2,000 | 2,000,000 | 0.002 | 2.6820442 |
| 5 | 5,000 | 5,000,000 | 0.005 | 6.7051104 |
| 10 | 10,000 | 10,000,000 | 0.01 | 13.410221 |
| 100 | 100,000 | 100,000,000 | 0.1 | 134.10221 |
What is a kilowatt?
A kilowatt is 1,000 W. Car engines, solar arrays, heat pumps and large appliances are rated in kW.
What is a watt?
The watt is the SI unit of power: one joule per second. Light bulbs, chargers and appliances are rated in watts.
Common mistakes to avoid
Confusing power (kw) with energy (kwh), and mechanical horsepower (745.7 w) with metric horsepower (735.5 w).
Formula
1 kW = 1,000 W1 kW = 1,000,000 mW1 kW = 0.001 MW1 kW = 1.3410221 hp1 kW = 1.3596216 PSWorked example
Inputs — From: 1 kW.
Results — To = 1,000 W; Milliwatts = 1,000,000 mW; Megawatts = 0.001 MW; Mechanical horsepower = 1.34102209 hp; Metric horsepower = 1.35962162 PS; BTU per hour = 3,412.14163313 BTU/h; Kilocalories per hour = 860.42065011 kcal/h.
Frequently asked questions
How many watts is 1 horsepower?
745.7 W (mechanical) or 735.5 W (metric PS).
What is a ton of refrigeration?
12,000 BTU/h, about 3.517 kW of cooling.
How many BTU/h is 1 kW?
About 3,412 BTU/h.
How do I change the units?
Pick any unit in the From and To menus. The value is converted in place, and the heading changes to show your conversion, for example “Kilowatts to Watts Converter”.
Can I type into any field?
Yes. Every field is editable, so you can start from whichever unit you have.
How many units can I convert between?
11 power units, from the everyday to the specialised.
Which units are exact?
All factors here are exact by definition except astronomical and similar reference values, which use internationally agreed constants.
What formula does the Power Converter use?
1 kW = 1,000 W.