Convert Watt-hours to Kilowatt-hours
1 watt-hour (Wh) equals 0.001 kilowatt-hours (kWh).
1 Wh = 0.001 kWh
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk watt-hour to kilowatt-hour converter to paste a column from Excel.
How to Convert Watt-hour to Kilowatt-hour
- 1 Wh = 0.001 kWh
- 1 kWh = 1000 Wh
- Example: convert 15 Wh to kWh: 15 Wh = 15 × 0.001 kWh = 0.015 kWh
Formula
kWh = Wh ÷ 1000
Derivation from SI units:
- 1 Wh = 1 W × 3600 s = 3600 J
- 1 kWh = 1000 W × 3600 s = 3.6 × 10⁶ J
- 1 Wh = 3600 J ÷ 3600000 J per kWh = 0.001 kWh
Both units are defined exactly, so the factor is exact. Watt-hour definition: watt-hour; Kilowatt-hour definition: kilowatt-hour.
Worked examples
- A reading of 20 Wh converts to 0.02 kWh.
20 Wh × 0.001 = 0.02 kWh - A value of 100 Wh is 0.1 kWh.
100 Wh × 0.001 = 0.1 kWh
Watt-hour to Kilowatt-hour conversion table
| Watt-hours (Wh) | Kilowatt-hours (kWh) |
|---|---|
| 1 Wh | 0.001 kWh |
| 5 Wh | 0.005 kWh |
| 10 Wh | 0.01 kWh |
| 15 Wh | 0.015 kWh |
| 20 Wh | 0.02 kWh |
| 50 Wh | 0.05 kWh |
| 60 Wh | 0.06 kWh |
| 75 Wh | 0.075 kWh |
| 100 Wh | 0.1 kWh |
| 160 Wh | 0.16 kWh |
| 500 Wh | 0.5 kWh |
| 1000 Wh | 1 kWh |
Where it's used
Watt-hours are used for battery capacity (phone ≈ 15 Wh; airline limit 100 Wh per power bank), while kilowatt-hours appear in electricity bills and meters. Both measure energy, work and heat, so the conversion is a fixed factor.
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 kilowatt-hours are in 1 watt-hour?
1 Wh = 0.001 kWh.
How do I convert watt-hours to kilowatt-hours?
Multiply the value in Wh by 0.001, or divide it by 1000. For example, 15 Wh × 0.001 = 0.015 kWh.
Is the Wh to kWh conversion exact?
Yes. Both units are defined exactly, and 1 Wh is exactly 0.001 kWh.
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)".
- 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, "kilowatt hour (kW·h)".
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 Kilowatt-hours. Retrieved October 17, 2026, from https://scientificconverters.com/energy/watt-hours-to-kilowatt-hours/
IEEE
Scientific Converters, "Convert Watt-hours to Kilowatt-hours," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/watt-hours-to-kilowatt-hours/