In 1 joules there are 2.77778e-7 kilowatt-hour. Meanwhile in 1 kilowatt-hour there are 3,600,000 joules. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Kilowatt-hour to Joules calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert joules (J) to kilowatt-hours (kWh), use the fixed unit link between watts, seconds, and hours.
Key facts
Joules to kWh formula
Quick example
Tip: If your value is very large in joules, the result in kilowatt-hours will often look much smaller because 3,600,000 joules make 1 kWh.
Use this formula:
That’s because 1 kWh = 3.6 million joules (3.6 × 10⁶ J).
A watt is 1 joule per second. A kilowatt is 1,000 watts. One hour has 3,600 seconds.
So:
The conversion factor is:
Many people find it easier to divide by 3,600,000 instead of using the factor.
Use the reverse conversion:
This is helpful for physics work and energy totals in joules.
1 joule is a very small amount of energy:
1 kilowatt-hour equals:
This is a common match-up between electricity use (kWh) and science units (J).
You can do it in two short steps:
Or use the direct method:
Example: Convert 7,200,000 J to kWh.
Joules per second is watts (W). To get kWh, you need time.
Example: 500 J/s for 2 hours
kWh is a unit of energy, not power.
Use joules (J) when working with physics formulas, motion, heat, and force. Use kilowatt-hours (kWh) for electrical energy use, billing, and appliance energy totals.
Both measure energy. They just fit different uses:
No. The conversion is fixed because both units measure energy. Temperature, voltage, and other values can change the energy you have, but they don’t change how joules convert to kWh.
Use the exact relationship:
Keep extra decimal places until the final step. Then round once, based on your need (billing, lab work, or reports).
The Calculate Box tool to convert joules to kilowatt-hour uses the open source script Convert.js to convert units of measurement. To use this tool, simply type a joules value in the box and have it instantly converted to kilowatt-hour.