Convert Joules to Watt-hours
J to Wh · energy conversion
What are joules and watt-hours?
The joule is the SI unit of energy, the work done by one newton acting over one meter. A watt-hour is the energy of one watt sustained for one hour, equal to 3,600 J. For reference: a food Calorie is one kilocalorie (4,184 J), and home electricity is billed in kilowatt-hours.
How to convert joules to watt-hours
1 J = 0.000277778 Wh. To convert, multiply the number of joules by 0.000277778. For example, 5 J = 0.00138889 Wh, and 20 J = 0.00555556 Wh. To go the other way, multiply watt-hours by 3,600 (since 1 Wh = 3,600 J).
Joules to Watt-hours conversion table
| Joules (J) | Watt-hours (Wh) |
|---|---|
| 1 | 0.000277778 |
| 10 | 0.00277778 |
| 100 | 0.0277778 |
| 500 | 0.138889 |
| 1,000 | 0.277778 |
| 2,000 | 0.555556 |
| 5,000 | 1.38889 |
FAQ
What is 1 J in Wh?
1 J = 0.000277778 Wh. To convert any amount, multiply the number of joules by 0.000277778.
How do I convert watt-hours back to joules?
Go the other way: 1 Wh = 3,600 J, so multiply watt-hours by 3,600 to get joules.
Is a joule bigger than a watt-hour?
No — 1 J is the smaller unit, equal to 0.000277778 Wh (it takes 3,600 J to make one Wh).
Are these energy conversions exact?
They use the standard internationally-defined conversion factors. Results are rounded to six significant figures for readability, which is accurate enough for everyday and most technical use.