How to Convert Watt-hours to Kilocalories (Wh to kcal)
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 kilocalories by hand, with examples and a quick-reference table.
The conversion
To convert watt-hours to kilocalories, multiply the value by 0.8604206501. To go the other way, divide by the same number (or multiply by 1.1622222222). For a quick estimate, multiply by about 0.86.
Kilocalories = watt-hours × 0.8604206501
Worked examples
- 3 Wh = 2.5813 kcal
- 12.5 Wh = 10.7553 kcal
- 75 Wh = 64.5315 kcal
Watt-hours to Kilocalories table
| Watt-hours | Kilocalories |
|---|---|
| 1 Wh | 0.860421 kcal |
| 2 Wh | 1.7208 kcal |
| 5 Wh | 4.3021 kcal |
| 10 Wh | 8.6042 kcal |
| 20 Wh | 17.2084 kcal |
| 25 Wh | 21.5105 kcal |
| 50 Wh | 43.021 kcal |
| 100 Wh | 86.0421 kcal |
| 250 Wh | 215.1052 kcal |
| 500 Wh | 430.2103 kcal |
| 1,000 Wh | 860.4207 kcal |
Common questions
Is Wh to kcal 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 Kilocalories to Watt-hours converter.
Mistakes to avoid
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.
Rounding the factor too early
Using 3 instead of 3.28 for feet per metre introduces an error of almost 9% before you have started.
Multiplying when you should divide
Converting to a smaller unit gives a bigger number, and converting to a larger unit gives a smaller one. If your answer moves the wrong way, you have inverted the factor.
Background
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
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 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.
For any value, use the Watt-hours to Kilocalories Converter or browse all energy converters.
Run your own numbers: Watt-hours to Kilocalories Converter