How to Convert Watt-hours to Kilowatt-hours (Wh to kWh)
Energy conversions link food labels in kJ and kcal, SP Group bills in kWh and air-conditioner capacity in BTU. This guide shows how to convert watt-hours into kilowatt-hours by hand, with examples and a quick-reference table.
The conversion
To convert watt-hours to kilowatt-hours, multiply the value by 0.001. To go the other way, divide by the same number (or multiply by 1,000). For a quick estimate, multiply by about 0.001.
Kilowatt-hours = watt-hours × 0.001
Worked examples
- 3 Wh = 0.003 kWh
- 12.5 Wh = 0.0125 kWh
- 75 Wh = 0.075 kWh
Watt-hours to Kilowatt-hours table
| Watt-hours | Kilowatt-hours |
|---|---|
| 1 Wh | 0.001 kWh |
| 2 Wh | 0.002 kWh |
| 5 Wh | 0.005 kWh |
| 10 Wh | 0.01 kWh |
| 20 Wh | 0.02 kWh |
| 25 Wh | 0.025 kWh |
| 50 Wh | 0.05 kWh |
| 100 Wh | 0.1 kWh |
| 250 Wh | 0.25 kWh |
| 500 Wh | 0.5 kWh |
| 1,000 Wh | 1 kWh |
Common questions
Is Wh to kWh exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the Kilowatt-hours to Watt-hours converter.
Mistakes to avoid
Mixing similar-sounding units
US and imperial gallons, pints and tons are different sizes, and decimal kilobytes differ from binary kibibytes.
Forgetting squared and cubed units
Area and volume factors are the length factor squared or cubed, so 1 m² is about 10.76 sq ft, not 3.28.
Dropping the units
A bare number without a unit is easy to misread later. Always write the unit with the result.
Background
Writing the units next to every number while you work is the simplest way to avoid mistakes. If the units do not cancel to leave the one you want, the calculation is set up wrongly.
For everyday use, three or four significant figures are usually enough. Engineering, science and trade documents may need more, and rounding should happen only at the end of a calculation.
Unit conversion is simply multiplication by a fixed ratio. The ratio between two units of the same quantity never changes, so once you know it you can convert any value in either direction.
For any value, use the Watt-hours to Kilowatt-hours Converter or browse all energy converters.
Run your own numbers: Watt-hours to Kilowatt-hours Converter