How many joules are in 1 kilowatt-hour?

1 kilowatt-hour equals 3600000 J.

How do I convert joules back to kilowatt-hours?

Use the reverse converter: 1 joule equals 2.77778e-7 kWh.

Yes. It uses the exact SI/NIST definitions of each unit and shows up to 6 significant digits.

To convert kilowatt-hours to joules, multiply the value by 3600000.

J = kWh × 3600000

40 kWh × 3600000 = 144000000 J

Kilowatt-hour (kWh): The unit on household electricity bills. Equal to 3.6 megajoules.
Joule (J): The SI unit of energy, one newton-metre, named after James Prescott Joule.

How do I convert kilowatt-hours to joules?: To convert kilowatt-hours to joules, multiply the value by 3600000.
How many joules are in 1 kilowatt-hour?: 1 kilowatt-hour equals 3600000 J.
How many joules are in 10 kilowatt-hours?: 10 kWh equals 36000000 J.
How do I convert joules back to kilowatt-hours?: Use the reverse converter: 1 joule equals 2.77778e-7 kWh.
Is this converter accurate?: Yes. It uses the exact SI/NIST definitions of each unit and shows up to 6 significant digits.