Calories to Kilowatt Hours
Convert calories (cal) to kilowatt hours (kWh). Both measure work and power, and the conversion comes up in nutrition, electricity, fitness work.
The Formula
``
kilowatt hours = calories × 0.00000116222222222
calories = kilowatt hours × 860420.650096
`
One calory is 1.1622e-6 kilowatt hours, and one kilowatt hour is 860,420.65 calories.
Conversion Table
| Calories | Kilowatt Hours |
|---|---|
| 1 cal | 1.1622e-6 kWh |
| 2 cal | 2.3244e-6 kWh |
| 5 cal | 5.8111e-6 kWh |
| 10 cal | 1.1622e-5 kWh |
| 25 cal | 2.9056e-5 kWh |
| 50 cal | 5.8111e-5 kWh |
| 100 cal | 1.1622e-4 kWh |
| 500 cal | 5.8111e-4 kWh |
| 1,000 cal | 0.001162 kWh |
The Other Direction
| Kilowatt Hours | Calories |
|---|---|
| 1 kWh | 860,420.65 cal |
| 2 kWh | 1,720,841.3 cal |
| 5 kWh | 4,302,103.25 cal |
| 10 kWh | 8,604,206.5 cal |
| 25 kWh | 21,510,516.25 cal |
| 50 kWh | 43,021,032.5 cal |
| 100 kWh | 86,042,065.01 cal |
| 500 kWh | 430,210,325.05 cal |
| 1,000 kWh | 860,420,650.1 cal |
What Each Unit Is
Calories (cal) — the energy to raise one gram of water by one degree Celsius, or 4.184 joules — the "small" calorie. A 19th-century thermal unit, displaced by the joule in physics but retained in nutrition.
Kilowatt Hours (kWh) — 1,000 watt-hours, or 3.6 million joules. The unit electricity has been billed in since metering began.
A Sense of Scale
A gram of sugar holds about 4,000 small calories- A home uses 8–30 kWh a day
- An EV takes 15–20 kWh per 100 km
Precision
The factor 0.00000116222222222 is rounded. For engineering work carry more digits than the table above, and round only at the end — rounding at each step compounds.
Watch Out For
- Food labels say "calorie" but mean kilocalorie — 1,000 of these. A 200-calorie snack is 200 kcal, or 837 kJ.
In Code
`javascript
const calorieToKilowattHour = (value) => value * 0.00000116222222222;
``
Where This Conversion Comes Up
- Nutrition
- Electricity
- Fitness
- Heating
- Fuel
How Many Decimals Do You Need?
Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 cal with the factor truncated at each decimal place:
| Decimals kept | Factor | 137 cal becomes | Error |
|---|---|---|---|
| 0 | 0 | 0 | 100.0000% |
| 1 | 0 | 0 | 100.0000% |
| 2 | 0 | 0 | 100.0000% |
| 3 | 0 | 0 | 100.0000% |
| 4 | 0 | 0 | 100.0000% |
The right number of significant figures is set by your input, not by the converter. If you measured calories to three significant figures, the answer in kilowatt hours is only good to three — writing more digits claims precision the measurement never had.