Energy Converter
Interactive StudioConvert between joules, kilojoules, megajoules, food calories (kcal), watt-hours, kilowatt-hours, megawatt-hours, BTU, and electronvolts. Instant feedback with zero server storage.
Loading tool…
About Energy Converter
Energy measures the quantitative property transferred to a body or physical system to perform work or heat.
Key Conversions: • 1 Kilowatt-Hour (kWh) = 3,600,000 Joules = 3.6 Megajoules (MJ) = 860.42 kcal. • 1 Food Calorie (kcal) = 4,184 Joules = 1.163 Watt-hours. • 1 BTU (British Thermal Unit) ≈ 1,055.06 Joules.
How to use Energy Converter
- Type the value you want to convert.
- Choose the unit you are converting from and the unit you want, such as joules, kilowatt-hours, kilocalories or BTU.
- Read the converted value instantly. Swap the units to convert the other way.
- Copy the result, or check other units listed in the results grid.
Worked examples
Input: 2 kWh to megajoules
Result: 7.2 MJ.
Input: 500 kcal to kilojoules
Result: 2,092 kJ.
Background
The joule is the SI unit of energy. A kilowatt-hour is 3,600,000 J, a food calorie (kcal) is 4,184 J, and a BTU is about 1,055.06 J. All conversions pass through joules.
Electricity bills use kWh, nutrition labels use kcal, and heating equipment often quotes BTU. Converting between them lets you compare, for example, the energy in food with the energy in a battery.
Common mistakes
- Confusing a calorie (cal) with a food Calorie (kcal). One kcal is 1,000 cal.
- Mixing up energy (kWh) and power (kW). Power is the rate, energy is power multiplied by time.
- Treating the many BTU variants as identical. The values differ slightly between definitions.
Frequently Asked Questions
Frequently Paired With
Fast, local-first developer micro-tools with zero tracking or latency.