10 units
Energy Converter
Convert between joules, calories, kWh, BTU and other energy units. Used in physics, electricity bills, nutrition labels and engineering.
Popular energy conversions
Common energy conversions
| From | Equivalent |
|---|---|
| 1 J | 0.001 kJ · 0.239006 cal · 0.000239 kcal · 0.000278 Wh · 2.7778e-7 kWh |
| 5 J | 0.005 kJ · 1.195029 cal · 0.001195 kcal · 0.001389 Wh · 1.3889e-6 kWh |
| 10 J | 0.01 kJ · 2.390057 cal · 0.00239 kcal · 0.002778 Wh · 2.7778e-6 kWh |
| 100 J | 0.1 kJ · 23.900574 cal · 0.023901 kcal · 0.027778 Wh · 2.7778e-5 kWh |
| 1000 J | 1 kJ · 239.005736 cal · 0.239006 kcal · 0.277778 Wh · 0.000278 kWh |
How the conversion works
Linear: 1 cal = 4.184 J, 1 kWh = 3,600,000 J = 3,412 BTU, 1 food kcal = 1,000 small cal = 4,184 J.
When you'll use this converter
- Electricity bills (kWh)
- Nutrition labels (kcal / food cal)
- HVAC and heating (BTU, therms)
- Physics and chemistry (J, eV)
Frequently asked
Is a food calorie the same as a calorie?
No — a food 'Calorie' (capital C) actually means 1 kilocalorie = 1,000 small calories = 4,184 J. Nutrition labels typically write 'cal' meaning kcal.
How many joules in 1 kWh?
1 kWh = 3,600,000 J (3.6 MJ). Because 1 kW × 1 hour = 1,000 W × 3,600 s = 3,600,000 J.
What is a BTU?
British Thermal Unit — the energy required to raise 1 pound of water by 1 °F. 1 BTU ≈ 1,055 J.