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Energy
Watt-hours to Kilocalories
Convert watt-hours (Wh) to kilocalories (kcal). Type a value below to see the result update instantly. Reference table and formula included.
Calculator
1 Wh = 0.860421 kcal
Watt-hours to Kilocalories Conversion Table
Common values, ready to copy:
| watt-hours | kilocalories |
|---|---|
| 1 Wh | 0.860421 kcal |
| 2 Wh | 1.7208 kcal |
| 5 Wh | 4.3021 kcal |
| 10 Wh | 8.6042 kcal |
| 25 Wh | 21.5105 kcal |
| 50 Wh | 43.021 kcal |
| 100 Wh | 86.0421 kcal |
| 1,000 Wh | 860.42 kcal |
Formula
kilocalories = watt-hours × 8.60420650e-1
Energy uses the SI joule. Food calories (kcal) are 1,000 small calories: 1 kcal = 4,184 J. 1 kWh = 3.6 MJ = 3,600,000 J. 1 BTU = 1,055.06 J.
About Watt-hours and Kilocalories
Watt-hours (Wh): The energy consumed by a 1-watt device in 1 hour; equals 3,600 joules. Common uses: Small battery capacities (laptop batteries are typically 40-100 Wh), and lighting energy use.
Kilocalories (kcal): A thousand small calories, or about 4,184 J; this is what 'calories' means on US food labels. Common uses: Food energy labeling in the US (a 'Calorie' on a US food label is a kilocalorie), nutrition tracking, and exercise energy expenditure.
How the conversion works
Energy uses the SI joule. Food calories (kcal) are 1,000 small calories: 1 kcal = 4,184 J. 1 kWh = 3.6 MJ = 3,600,000 J. 1 BTU = 1,055.06 J.
The exact relationship is kilocalories = watt-hours × 8.60420650e-1, which the calculator at the top of this page applies in both directions. Type into either field and the other updates immediately.
When this conversion matters
Converting between watt-hours and kilocalories comes up wherever energy measurements move between systems — from one country's conventions to another's, from a scientific reference to a practical specification, or from one industry's working unit to another's. The calculator and reference table above cover the everyday range; for unusual values you can type any number into either field.