Joules to Watt-hours
Type a value in Joules and get the result in Watt-hours, calculated exactly.
100 Joules ≈ 0.02777777778 Watt-hours
Precision
Exact factorRounded for display to about 10 significant digits.
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Formula
Wh = J ÷ 3,600
To convert Joules to Watt-hours, divide the value by 3,600.
Worked examples
- 1 J ÷ 3,600 ≈ 0.000277777778 Wh
- 100 J ÷ 3,600 ≈ 0.02777777778 Wh
- 50 J ÷ 3,600 ≈ 0.01388888889 Wh
This factor is exact by definition.
Conversion table
| Joules (J) | Watt-hours (Wh) |
|---|---|
| 1 | ≈ 0.0002777778 |
| 2 | ≈ 0.0005555556 |
| 3 | ≈ 0.0008333333 |
| 4 | ≈ 0.001111111 |
| 5 | ≈ 0.001388889 |
| 6 | ≈ 0.001666667 |
| 7 | ≈ 0.001944444 |
| 8 | ≈ 0.002222222 |
| 9 | 0.0025 |
| 10 | ≈ 0.002777778 |
| 15 | ≈ 0.004166667 |
| 20 | ≈ 0.005555556 |
| 25 | ≈ 0.006944444 |
| 30 | ≈ 0.008333333 |
| 40 | ≈ 0.01111111 |
| 50 | ≈ 0.01388889 |
| 60 | ≈ 0.01666667 |
| 70 | ≈ 0.01944444 |
| 75 | ≈ 0.02083333 |
| 80 | ≈ 0.02222222 |
| 90 | 0.025 |
| 100 | ≈ 0.02777778 |
Values marked ≈ are rounded; the rest are exact.
Reverse table: Watt-hours to Joules
| Watt-hours (Wh) | Joules (J) |
|---|---|
| 1 | 3,600 |
| 2 | 7,200 |
| 3 | 10,800 |
| 4 | 14,400 |
| 5 | 18,000 |
| 6 | 21,600 |
| 7 | 25,200 |
| 8 | 28,800 |
| 9 | 32,400 |
| 10 | 36,000 |
| 15 | 54,000 |
| 20 | 72,000 |
| 25 | 90,000 |
| 30 | 108,000 |
| 40 | 144,000 |
| 50 | 180,000 |
| 60 | 216,000 |
| 70 | 252,000 |
| 75 | 270,000 |
| 80 | 288,000 |
| 90 | 324,000 |
| 100 | 360,000 |
Unit definitions
- Joules J
- The SI unit of energy: one newton acting over one metre, or one watt for one second.
- Watt-hours Wh
- One watt for one hour: exactly 3600 joules.
Questions people ask
Joules to Watt-hours: what is the conversion factor?
One J is ≈ 0.000277777778 Wh.
How do I convert Joules to Watt-hours?
Use the formula above. For example, 100 J = ≈ 0.02777777778 Wh.
Is the conversion exact?
Yes. Both units have exact definitions, so the factor is exact; a result is only rounded when its decimals never end.
Factors checked 19 October 2026.