Calories to Watt Hours
Type a value in either box to convert between calories and watt hours. The factor is 0.00116222.
| Calories | Watt Hours |
|---|---|
| 1 cal | 0.001162 Wh |
| 2 cal | 0.002324 Wh |
| 3 cal | 0.003487 Wh |
| 5 cal | 0.005811 Wh |
| 10 cal | 0.011622 Wh |
| 25 cal | 0.029056 Wh |
| 50 cal | 0.058111 Wh |
| 100 cal | 0.116222 Wh |
How to use
- Enter a value in the Calories field.
- The Watt Hours figure appears immediately — no button to press.
- Typing in the Watt Hours field converts back to Calories the same way.
- Use the reference table for the values that come up most often.
Calories to Watt Hours formula
To convert calories to watt hours, multiply by 0.00116222222.
Wh = cal × 0.00116222222
Why this factor: the calorie and the watt-hour are both defined against the joule, so dividing one definition by the other gives 0.00116222222 directly. Both definitions are set out in full below.
To go the other way, divide by 0.00116222222 — or use the Watt Hours to Calories converter, which is the same calculation reversed.
Worked example
Start with 100 cal. Multiply by 0.00116222222 to get 0.116222 Wh.
100 cal × 0.00116222222 = 0.116222 Wh
The converter above does this for any value you type, in either direction.
What is a calorie?
A calorie is the energy needed to warm one gram of water by one degree Celsius.
Definition: The thermochemical calorie is defined as exactly 4.184 joules.
Where it is used: Chemistry and physics literature, and older engineering references.
Worth knowing: The 'calories' on a nutrition label are actually kilocalories — 1,000 of these. A 500-Calorie meal is 500 kcal, or about 2.1 million joules.
What is a watt-hour?
A watt-hour is the energy delivered by one watt of power sustained for one hour.
Definition: Exactly 3,600 joules.
Where it is used: Battery capacity for laptops, e-bikes and power tools, and small-scale energy metering.
Worth knowing: Airline lithium-battery limits are set in watt-hours, which is why laptop and power-bank capacities are labelled in Wh.
Calories vs Watt Hours
The calorie and the watt-hour belong to the same family of units, so converting between them is usually a matter of shifting a decimal point or applying a small whole-number factor.
Frequently asked questions
How many watt hours are in a calorie?
One calorie equals 0.00116222222 watt hours.
What is the formula to convert calories to watt hours?
Multiply the number of calories by 0.00116222222. To reverse it, divide by 0.00116222222 instead.
How do I convert watt hours back to calories?
Divide by 0.00116222222, which is the same as multiplying by 860.42065.
How many watt hours are in 10 calories?
10 cal works out to 0.011622 Wh.
Is there anything to watch out for with calories?
The 'calories' on a nutrition label are actually kilocalories — 1,000 of these. A 500-Calorie meal is 500 kcal, or about 2.1 million joules.
How is the calorie defined?
The thermochemical calorie is defined as exactly 4.184 joules.