Convert Watt-hours to Calories
1 watt-hour is 860.42065 cal. One watt-hour is exactly 860.420650096 calories.
One watt-hour is 860.42065 calories. To convert watt-hours to calories, multiply by 860.42065; to go the other way, divide by 860.42065 or multiply by 0.0011622222. 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 × 860.42065
value * 860.420650096860.421 cal
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 calories?
- 1.Take the measurement in watt-hours.
- 2.Multiply by 860.42065 — that is how many calories fit in one watt-hour.
- 3.To go back the other way, divide by 860.42065, or multiply by 0.0011622222.
Worked example: 25 watt-hours to calories
- Formula
- Wh × 860.42065 = cal
- Arithmetic
- 25 × 860.42065 = 21,510.516252 cal
- Answer
- 25 Wh = 21,510.516252 cal
The factor is rounded for display; the figure above is computed from the full value.
Watt-hours to calories conversion table
| Watt-hours | Calories |
|---|---|
| 1 Wh | 860.42065 cal |
| 2 Wh | 1,720.8413 cal |
| 3 Wh | 2,581.26195 cal |
| 4 Wh | 3,441.6826 cal |
| 5 Wh | 4,302.10325 cal |
| 6 Wh | 5,162.523901 cal |
| 7 Wh | 6,022.944551 cal |
| 8 Wh | 6,883.365201 cal |
| 9 Wh | 7,743.785851 cal |
| 10 Wh | 8,604.206501 cal |
| 12 Wh | 10,325.047801 cal |
| 15 Wh | 12,906.309751 cal |
| 20 Wh | 17,208.413002 cal |
| 25 Wh | 21,510.516252 cal |
| 50 Wh | 43,021.032505 cal |
| 100 Wh | 86,042.06501 cal |
| 200 Wh | 172,084.130019 cal |
| 300 Wh | 258,126.195029 cal |
| 500 Wh | 430,210.325048 cal |
| 1000 Wh | 860,420.650096 cal |
| 2000 Wh | 1,720,841.300192 cal |
| 5000 Wh | 4,302,103.25048 cal |
| 10000 Wh | 8,604,206.50096 cal |
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 calorie?
The thermochemical calorie: exactly 4.184 joules by definition. This is the small calorie — the one on a food label is a thousand of these, which is the single most common confusion in this group.
How many calories are in a watt-hour?
One watt-hour is 860.42065 calories. Going the other way, one calorie is 0.0011622222 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 calories are in a watt-hour?
- 860.42065. The thermochemical calorie: exactly 4.184 joules by definition. This is the small calorie — the one on a food label is a thousand of these, which is the single most common confusion in this group.
- How do I convert calories back to watt-hours?
- Divide by 860.42065, or multiply by 0.0011622222 — they are the same operation.
Other energy conversions
Calories to watt-hours — the same conversion the other way.