Convert Watt-hours to Kilocalories
1 watt-hour is 0.860421 kcal. One watt-hour is exactly 0.860420650096 kilocalories.
One watt-hour is 0.86042065 kilocalories. To convert watt-hours to kilocalories, multiply by 0.86042065; to go the other way, divide by 0.86042065 or multiply by 1.1622222. The factor is exact rather than rounded: it follows from NIST Special Publication 811. One watt sustained for an hour, so exactly 3,600 joules.
Factor checked against the defining standard · How we check
- Watt-hours × 0.86042065
value * 0.8604206500960.86 kcal
1 watt-hour in every energy unit
| Unit | Value | Exact factor |
|---|---|---|
| joules | 3,600 J | × 3,600 |
| kilojoules | 3.6 kJ | × 3.6 |
| calories | 860.4206501 cal | × 860.420650096 |
| kilocalories | 0.8604206501 kcal | × 0.860420650096 |
| watt-hours (as entered) | 1 Wh | — |
| kilowatt-hours | 0.001 kWh | × 0.001 |
| British thermal units | 3.412141633 BTU | × 3.41214163313 |
| foot-pounds | 2,655.223737 ft·lbf | × 2,655.2237374 |
Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert watt-hours to kilocalories?
- 1.Take the measurement in watt-hours.
- 2.Multiply by 0.86042065 — that is how many kilocalories fit in one watt-hour.
- 3.To go back the other way, divide by 0.86042065, or multiply by 1.1622222.
Worked example: 25 watt-hours to kilocalories
- Formula
- Wh × 0.86042065 = kcal
- Arithmetic
- 25 × 0.86042065 = 21.510516 kcal
- Answer
- 25 Wh = 21.510516 kcal
The factor is rounded for display; the figure above is computed from the full value.
Watt-hours to kilocalories conversion table
| Watt-hours | Kilocalories |
|---|---|
| 1 Wh | 0.860421 kcal |
| 2 Wh | 1.720841 kcal |
| 3 Wh | 2.581262 kcal |
| 4 Wh | 3.441683 kcal |
| 5 Wh | 4.302103 kcal |
| 6 Wh | 5.162524 kcal |
| 7 Wh | 6.022945 kcal |
| 8 Wh | 6.883365 kcal |
| 9 Wh | 7.743786 kcal |
| 10 Wh | 8.604207 kcal |
| 12 Wh | 10.325048 kcal |
| 15 Wh | 12.90631 kcal |
| 20 Wh | 17.208413 kcal |
| 25 Wh | 21.510516 kcal |
| 50 Wh | 43.021033 kcal |
| 100 Wh | 86.042065 kcal |
| 200 Wh | 172.08413 kcal |
| 300 Wh | 258.126195 kcal |
| 500 Wh | 430.210325 kcal |
| 1000 Wh | 860.42065 kcal |
| 2000 Wh | 1,720.8413 kcal |
| 5000 Wh | 4,302.10325 kcal |
| 10000 Wh | 8,604.206501 kcal |
What is a watt-hour?
One watt sustained for an hour, so exactly 3,600 joules. Battery capacity is quoted here because it is an amount of energy rather than a rate.
What is a kilocalorie?
A thousand small calories, and what a food label means by "Calories" with a capital C. A 2,000 calorie diet is 2,000 kcal, or 8.4 megajoules.
How many kilocalories are in a watt-hour?
One watt-hour is 0.86042065 kilocalories. Going the other way, one kilocalorie is 1.1622222 watt-hours. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every energy unit here
| Unit | Symbol | One of these is |
|---|---|---|
| Joules | J | the base unit |
| Kilojoules | kJ | 1000 joule |
| Calories | cal | 4.184 joule |
| Kilocalories | kcal | 4184 joule |
| Watt-hours | Wh | 3600 joule |
| Kilowatt-hours | kWh | 3600000 joule |
| British thermal units | BTU | 1055.0559 joule |
| Foot-pounds | ft·lbf | 1.3558179 joule |
Source: NIST Special Publication 811 — the thermochemical calorie is exactly 4.184 J
Questions people actually ask
- How many kilocalories are in a watt-hour?
- 0.86042065. A thousand small calories, and what a food label means by "Calories" with a capital C. A 2,000 calorie diet is 2,000 kcal, or 8.4 megajoules.
- How do I convert kilocalories back to watt-hours?
- Divide by 0.86042065, or multiply by 1.1622222 — they are the same operation.
Other energy conversions
Kilocalories to watt-hours — the same conversion the other way.