Energy Converter
Convert between joules, kWh, BTU, calories, and more.
J (Joule)
4184
kJ (Kilojoule)
4.184
MJ (Megajoule)
0.004184
cal (calorie)
1000
kcal (kilocalorie)
1
Wh (Watt-hour)
1.1622222
kWh (Kilowatt-hour)
0.0011622222
MWh (Megawatt-hour)
1.162222e-6
BTU (British Thermal Unit)
3.9656668
Therm (US)
3.965667e-5
eV (Electronvolt)
2.611447e+22
ft·lb (foot-pound)
3085.96
About This Tool
The Energy Converter provides instant conversion between 12 common energy units including joules, kilocalories, kilowatt-hours, BTU, and more.
Compare food calories, electrical energy, and physical quantities all in one view, from electronvolts to megawatt-hours.
How to Use
- Enter a numeric value.
- Select the source unit.
- All conversions update instantly.
Reference
- 1 kcal (food calorie) = 4,184 J = 1.163 Wh
- 1 kWh = 3,600 kJ = 860 kcal = 3,412 BTU
- 1 BTU = 1,055 J ≈ 252 cal
- 1 Therm = 100,000 BTU ≈ 29.3 kWh
Use Cases
Nutritionists convert food calories to joules. Engineers convert BTU to kilowatt-hours. Physicists convert electronvolts to joules. Energy analysts compare fuel energy densities.
FAQ
- What's the difference between cal and kcal? — A "calorie" in food context (Cal) is actually a kilocalorie (1000 cal). 1 kcal = 4,184 J.
- What is a kWh? — A kilowatt-hour is the energy used by a 1 kW device running for 1 hour. It is the standard unit for electrical billing.