Watt Hours to Kilocalories
Type a value in either box to convert between watt hours and kilocalories. The factor is 0.860421.
| Watt Hours | Kilocalories |
|---|---|
| 1 Wh | 0.860421 kcal |
| 2 Wh | 1.720841 kcal |
| 3 Wh | 2.581262 kcal |
| 5 Wh | 4.302103 kcal |
| 10 Wh | 8.604207 kcal |
| 25 Wh | 21.510516 kcal |
| 50 Wh | 43.021033 kcal |
| 100 Wh | 86.042065 kcal |
How to use
- Enter a value in the Watt Hours field.
- The Kilocalories figure appears immediately — no button to press.
- Typing in the Kilocalories field converts back to Watt Hours the same way.
- Use the reference table for the values that come up most often.
Watt Hours to Kilocalories formula
Converting watt hours to kilocalories is a single multiplication by 0.86042065.
kcal = Wh × 0.86042065
Put another way, one watt-hour is exactly 450/523 kilocalories.
Why this factor: the watt-hour and the kilocalorie are both defined against the joule, so dividing one definition by the other gives 0.86042065 directly. Both definitions are set out in full below.
To go the other way, divide by 0.86042065 — or use the Kilocalories to Watt Hours converter, which is the same calculation reversed.
Worked example
Start with 100 Wh. Multiply by 0.86042065 to get 86.042065 kcal.
100 Wh × 0.86042065 = 86.042065 kcal
The converter above does this for any value you type, in either direction.
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.
What is a kilocalorie?
A kilocalorie is 1,000 calories, and is what food labeling calls a 'Calorie'.
Definition: Exactly 4,184 joules.
Where it is used: Nutrition and dietary energy in the US and much of the world, and metabolic measurements.
Worth knowing: Written with a capital C ('Calorie') or as 'kcal' on labels. This is the unit meant by everyday talk about counting calories.
Watt Hours vs Kilocalories
The watt-hour and the kilocalorie 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 kilocalories are in a watt-hour?
One watt-hour equals 0.86042065 kilocalories.
What is the formula to convert watt hours to kilocalories?
Multiply the number of watt hours by 0.86042065. To reverse it, divide by 0.86042065 instead.
How do I convert kilocalories back to watt hours?
Divide by 0.86042065, which is the same as multiplying by 1.16222222.
How many kilocalories are in 10 watt hours?
10 Wh works out to 8.604207 kcal.
Is there anything to watch out for with watt hours?
Airline lithium-battery limits are set in watt-hours, which is why laptop and power-bank capacities are labelled in Wh.
How is the watt-hour defined?
Exactly 3,600 joules.