Joules to Kilowatt-hours Converter
Convert joules or megajoules into the kilowatt-hours used for electricity billing.
How the conversion works
Joules are the SI unit of energy, but electricity is billed in kilowatt-hours. To convert joules to kWh, divide by 3,600,000 — the number of joules in one kilowatt-hour.
This is the reverse of the kWh-to-joules conversion. It is handy when a device or physics problem gives you energy in joules or megajoules and you want to know the equivalent on an electricity bill.
kWh = J ÷ 3,600,000Divide joules by 3.6 million (or megajoules by 3.6) to get kilowatt-hours.
Conversion table
| Joules | Kilowatt-hours | Watt-hours |
|---|---|---|
| 360,000 J | 0.1 kWh | 100 Wh |
| 1,000,000 J | 0.2778 kWh | 277.8 Wh |
| 3,600,000 J | 1 kWh | 1,000 Wh |
| 7,200,000 J | 2 kWh | 2,000 Wh |
| 18,000,000 J | 5 kWh | 5,000 Wh |
| 36,000,000 J | 10 kWh | 10,000 Wh |
Frequently asked questions
How do you convert joules to kWh?
Divide the energy in joules by 3,600,000. For example, 5,000,000 J ÷ 3,600,000 ≈ 1.389 kWh.
How many joules make 1 kWh?
3,600,000 joules equal one kilowatt-hour, so it takes 3.6 million joules to make a single kWh.
What is 1 megajoule in kWh?
One megajoule (1,000,000 J) is about 0.2778 kWh, because 1,000,000 ÷ 3,600,000 ≈ 0.2778.