Energy Converter
Convert between joules, kilojoules, calories, kilocalories, watt-hours, kilowatt-hours, BTUs, electronvolts, and foot-pounds.
| From | To | Result |
|---|---|---|
| 1 kcal | kJ | 4.184 kJ |
| 1 kWh | MJ | 3.6 MJ |
| 1 kWh | BTU | 3,412.14 BTU |
| 1 BTU | kJ | 1.05506 kJ |
| 1 kcal | Wh | 1.16222 Wh |
| 1 kJ | kcal | 0.239006 kcal |
| 1 J | cal | 0.239006 cal |
| 1 ft·lb | J | 1.35582 J |
Frequently Asked Questions
About This Energy Converter
This free energy converter converts between joules, kilojoules, calories, kilocalories, watt-hours, kilowatt-hours, electron volts, BTUs, and other energy units. Enter a value in any unit for instant results across all supported units.
When to use this converter
- Converting food energy between kcal and kJ
- Comparing electricity consumption figures in kWh
- Translating physics problems between SI and imperial energy units
Standards & References
How It Works
Enter Energy
Enter any energy value. All conversions use the joule (J) as the SI base unit of energy.
Pick Units
Choose from 10 energy units spanning everyday food calories to scientific electronvolts and engineering BTUs.
Instant Result
Results are shown instantly. Use the swap button to reverse the conversion and the reference table for quick lookups.
Common Use Cases
Nutrition & Fitness
Convert food energy between kcal and kJ for reading international nutrition labels and comparing dietary energy content.
Electricity Bills
Convert between kWh and joules/MJ to understand energy consumption on utility bills and compare costs of different energy sources.
Heating & Cooling
Convert HVAC ratings between BTU and kW/kJ for comparing heating/cooling equipment specifications across US and international markets.
Renewable Energy
Convert solar panel output, battery capacity, and energy storage between Wh, kWh, and MJ for renewable energy system design.
Physics & Chemistry
Convert between joules, electronvolts, and calories for thermodynamics problems, chemical reaction energies, and quantum physics.
Fuel & Combustion
Convert fuel calorific values between BTU, kJ, and MJ for comparing energy densities of natural gas, coal, oil, and biofuels.
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