⚡
Energy
Convert Joules, Calories, Kilowatt-hours, BTU
Popular Conversions
Convert All Units at Once
⚡
Convert All Units at Once
Type a value in any field — all others update instantly
Joule
J
Kilojoule
kJ
Calorie
cal
Kilocalorie
kcal
watt hour
Wh
kilowatt hour
kWh
electronvolt
eV
British thermal unit
BTU
💡 Click any unit field and type a value. All other units will calculate and display results simultaneously in real-time.
Supported Units of Energy
J
Joule
SI unit of energy
kJ
Kilojoule
1000 joules
cal
Calorie
Energy to heat 1 gram of water by 1°C
kcal
Kilocalorie
Food energy unit
Wh
watt hour
3600 joules
kWh
kilowatt hour
Electrical energy unit
eV
electronvolt
Energy of one electron accelerated through 1 volt
BTU
British thermal unit
Imperial unit of energy