Energy converter
Specify the energy value and the source and target units to convert to J, kWh, cal, eV, BTU and more. Express electrical energy or heat in the same unit. Copy the converted result.
What you can do
Align units of electrical and thermal energy
Convert from J, Wh, kWh, cal and other units to the unit you need.
Check the definitions used
Check the definitions of the thermochemical calorie and International Table BTU, and use them in accordance with the conditions in your reference.
How to use
Enter energy and its original unit
Specify the value to convert and the unit stated in your reference.
Choose the target unit
Choose the unit to use for comparison or recording.
Check the result
Press Convert, then check the original conditions and result. You can copy it if needed.
Useful when
Convert electrical energy to joules
Convert electrical energy stated in kWh to J or MJ for physics calculations.
Compare thermal energy representations
Use this to compare energy units, such as cal or BTU, that differ between references.
Energy units and definitions
kW and kWh are different quantities
kW is power, and kWh is energy. 1kWh is 3,600,000J. This screen converts energy units.
cal uses the thermochemical definition
Calculations use 1cal = 4.184J and 1kcal = 4,184J. Check the conditions in references that use a different definition of the calorie.
BTU uses the International Table factor
This screen calculates using 1BTU = 1,055.05585262J. Distinguish this from quantities per unit time such as BTU/h.
Frequently asked questions
Can I calculate electricity charges?
This screen converts energy units. It does not handle unit prices or contract conditions.
Are cal and kcal the same?
1kcal is 1000cal. Check the units in your reference before entering a value.
Can I convert kW to kWh?
Calculating energy from power requires conditions such as time. This screen does not handle that calculation.
Input and results
- Input
- An energy value, its original unit and the target unit.
- Results
- Energy in the selected unit.
- Copy
- Copy the displayed conversion result. Changing the input clears the previous result.