Convert Watt-hours to Joules
1 watt-hour (Wh) equals 3600 joules (J).
1 Wh = 3600 J
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk watt-hour to joule converter to paste a column from Excel.
How to Convert Watt-hour to Joule
- 1 Wh = 3600 J
- 1 J = 0.0002777777778 Wh
- Example: convert 15 Wh to J: 15 Wh = 15 × 3600 J = 54000 J
Formula
J = Wh × 3600
Derivation from SI units:
- 1 Wh = 1 W × 3600 s = 3600 J
- 1 J = 1 N·m = 1 W·s = 1 kg·m²·s⁻²
Both units are defined exactly, so the factor is exact. Watt-hour definition: watt-hour; Joule definition: joule.
Worked examples
- A 100 Wh power bank stores 360000 J.
100 Wh × 3600 = 360000 J - A 15 Wh phone battery holds 54000 J.
15 Wh × 3600 = 54000 J
Watt-hour to Joule conversion table
| Watt-hours (Wh) | Joules (J) |
|---|---|
| 1 Wh | 3600 J |
| 5 Wh | 18000 J |
| 10 Wh | 36000 J |
| 15 Wh | 54000 J |
| 20 Wh | 72000 J |
| 50 Wh | 180000 J |
| 60 Wh | 216000 J |
| 75 Wh | 270000 J |
| 100 Wh | 360000 J |
| 160 Wh | 576000 J |
| 500 Wh | 1800000 J |
| 1000 Wh | 3600000 J |
Where it's used
Battery capacities in Wh are converted to joules for physics problems and SI energy balances. Multiply by 3600.
Watt-hour to other energy units
| Conversion | 1 Wh equals |
|---|---|
| watt-hour to joule | 3600 J |
| watt-hour to kilojoule | 3.6 kJ |
| watt-hour to megajoule | 0.0036 MJ |
| watt-hour to calorie | 860.4206501 cal |
| watt-hour to kilocalorie | 0.8604206501 kcal |
| watt-hour to kilowatt-hour | 0.001 kWh |
| watt-hour to BTU | 3.412141633 BTU |
| watt-hour to therm | 0.00003412956341 thm |
| watt-hour to electronvolt | 2.246943267 × 10²² eV |
| watt-hour to foot-pound | 2655.223737 ft·lbf |
| watt-hour to erg | 36000000000 erg |
Frequently asked questions
How many joules is 1 Wh?
Exactly 3600 J.
How many joules are in 1 watt-hour?
1 Wh = 3600 J.
How do I convert watt-hours to joules?
Multiply the value in Wh by 3600. For example, 15 Wh × 3600 = 54000 J.
Is the Wh to J conversion exact?
Yes. Both units are defined exactly, and 1 Wh is exactly 3600 J.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "watt hour (W·h)".
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4, coherent derived units with special names.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Watt-hours to Joules. Retrieved October 17, 2026, from https://scientificconverters.com/energy/watt-hours-to-joules/
IEEE
Scientific Converters, "Convert Watt-hours to Joules," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/watt-hours-to-joules/