Energy Units

Find the right formula and tools for all energy units. We use official rules to make sure every calculation is correct.

All Energy Unit Pairs

Pick a starting unit to see all possible conversion tools for energy.

Our Standard Unit: Joules (J)

We calculate all energy units based on the standard Joules (J). This helps us keep all our tools accurate and reliable.

Conversion Formulas

Below is the list of rules we use to calculate each energy unit. You can use these to understand the math behind our tools.

Kilojoules (kJ)

Formula: 1 Kilojoules = 1000 Joules
To do the math instantly, use our kilojoules to joules or joules to kilojoules tools.

Megajoules (MJ)

Formula: 1 Megajoules = 1000000 Joules
To do the math instantly, use our megajoules to joules or joules to megajoules tools.

Gigajoules (GJ)

Formula: 1 Gigajoules = 1000000000 Joules
To do the math instantly, use our gigajoules to joules or joules to gigajoules tools.

Watt-hours (Wh)

Formula: 1 Watt-hours = 3600 Joules
To do the math instantly, use our watt-hours to joules or joules to watt-hours tools.

Kilowatt-hours (kWh)

Formula: 1 Kilowatt-hours = 3600000 Joules
To do the math instantly, use our kilowatt-hours to joules or joules to kilowatt-hours tools.

Megawatt-hours (MWh)

Formula: 1 Megawatt-hours = 3600000000 Joules
To do the math instantly, use our megawatt-hours to joules or joules to megawatt-hours tools.

Calories (IT) (cal)

Formula: 1 Calories = 4.1868 Joules
To do the math instantly, use our calories to joules or joules to calories tools.

Kilocalories (kcal)

Formula: 1 Kilocalories = 4186.8 Joules
To do the math instantly, use our kilocalories to joules or joules to kilocalories tools.

BTU (IT)

Formula: 1 BTU = 1055.06 Joules
To do the math instantly, use our btu to joules or joules to btu tools.

Therms (US)

Formula: 1 Therms = 105480400 Joules
To do the math instantly, use our therms to joules or joules to therms tools.

Electron-volts (eV)

Formula: 1 Electron-volts = 1.60218e-19 Joules
To do the math instantly, use our electron-volts to joules or joules to electron-volts tools.

Ergs

Formula: 1 Ergs = 1e-7 Joules
To do the math instantly, use our ergs to joules or joules to ergs tools.

Newton-meters (Nm)

Formula: 1 Newton-meters = 1 Joules
To do the math instantly, use our newton-meters to joules or joules to newton-meters tools.

Foot-pounds (ft-lb)

Formula: 1 Foot-pounds = 1.35582 Joules
To do the math instantly, use our foot-pounds to joules or joules to foot-pounds tools.

Kiloton TNT Yield

Formula: 1 Kiloton TNT Yield = 4184000000000 Joules
To do the math instantly, use our kiloton tnt yield to joules or joules to kiloton tnt yield tools.

All Systems

Compare these units against other measurement systems on our homepage.

All Unit Conversion Systems

Access our high-fidelity calculators for other measurement systems and engineering metrics.