Convert Calories to Watt-hours
One calorie equals 0.00116222 watt-hours. Type any value to convert calories to watt-hours instantly — with a full reference table below.
Convert Calories to Watt-hours
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How to convert Calories to Watt-hours
To convert calories to watt-hours, multiply by 0.00116222. One calorie equals 0.00116222 Wh, and one watt-hour equals 860.4207 cal.
- Take the value in calories — for example 7.5 cal.
- Multiply by 0.00116222 (the number of watt-hours in one calorie).
- 7.5 × 0.00116222 = 0.00871667 Wh.
Quick mental estimate: Divide the number of calories by 860 (accurate to better than 0.05%).
Calories to Watt-hours conversion table
| Calories | Watt-hours |
|---|---|
| 1 cal | 0.00116222 Wh |
| 2 cal | 0.00232444 Wh |
| 5 cal | 0.00581111 Wh |
| 10 cal | 0.0116222 Wh |
| 20 cal | 0.0232444 Wh |
| 50 cal | 0.0581111 Wh |
| 100 cal | 0.116222 Wh |
| 200 cal | 0.232444 Wh |
| 500 cal | 0.581111 Wh |
| 1,000 cal | 1.162222 Wh |
| 2,000 cal | 2.324444 Wh |
| Watt-hours | Calories |
|---|---|
| 1 Wh | 860.4207 cal |
| 2 Wh | 1,720.841 cal |
| 5 Wh | 4,302.103 cal |
| 10 Wh | 8,604.207 cal |
| 20 Wh | 17,208.41 cal |
| 50 Wh | 43,021.03 cal |
| 100 Wh | 86,042.07 cal |
| 200 Wh | 172,084.1 cal |
| 500 Wh | 430,210.3 cal |
| 1,000 Wh | 860,420.7 cal |
| 2,000 Wh | 1,720,841 cal |
About converting Calories to Watt-hours
Calories (cal) and Watt-hours (Wh) are both units of energy. The exact factor is 1 cal = 0.00116222 Wh, so multiply by 0.00116222 to go from calories to watt-hours (or divide to go back).
The conversion runs entirely in your browser. Need the reverse? Use the Watt-hours to Calories converter, or the full unit converter for every unit at once.
Real-world energy in calories and watt-hours
| Example | Calories | Watt-hours |
|---|---|---|
| One food Calorie (kcal) | 1,000 cal | 1.162222 Wh |
| A 100 W bulb running for one hour | 86,042.07 cal | 100 Wh |
| A smartphone battery (≈19 Wh) | ≈ 16,563.1 cal | ≈ 19.25 Wh |
| One kilowatt-hour | 860,420.7 cal | 1,000 Wh |
“≈” marks typical values; the rest are defined or measured figures.
The units
The thermochemical calorie: exactly 4.184 J — energy to warm 1 g of water by about 1 °C.
Used for: Chemistry. Food 'Calories' are kilocalories.
One watt for one hour: exactly 3,600 J.
Used for: Battery capacity (power banks, laptops).
The thermochemical calorie is exactly 4.184 J and a kilowatt-hour is exactly 3.6 MJ, so these factors are exact.