Convert Watt-hours to Calories
1 watt-hour (Wh) equals 860.4206501 calories (cal).
1 Wh = 860.4206501 cal
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk watt-hour to calorie converter to paste a column from Excel.
How to Convert Watt-hour to Calorie
- 1 Wh = 860.4206501 cal
- 1 cal = 0.001162222222 Wh
- Example: convert 15 Wh to cal: 15 Wh = 15 × 860.4206501 cal = 12906.30975 cal
Reference conditions. cal: Thermochemical calorie, 4.184 J exactly. The International Table calorie is 4.1868 J.
Formula
cal = Wh × 860.4206500956
Derivation from SI units:
- 1 Wh = 1 W × 3600 s = 3600 J
- 1 cal (thermochemical) = 4.184 J (exact)
- 1 Wh = 3600 J ÷ 4.184 J per cal = 860.4206500956 cal
Both units are defined exactly, so the factor is exact. Watt-hour definition: watt-hour; Calorie definition: calorie.
Worked examples
- A reading of 20 Wh converts to 17208.413 cal.
20 Wh × 860.4206501 = 17208.413 cal - A value of 100 Wh is 86042.06501 cal.
100 Wh × 860.4206501 = 86042.06501 cal
Watt-hour to Calorie conversion table
| Watt-hours (Wh) | Calories (cal) |
|---|---|
| 1 Wh | 860.4206501 cal |
| 5 Wh | 4302.10325 cal |
| 10 Wh | 8604.206501 cal |
| 15 Wh | 12906.30975 cal |
| 20 Wh | 17208.413 cal |
| 50 Wh | 43021.0325 cal |
| 60 Wh | 51625.23901 cal |
| 75 Wh | 64531.54876 cal |
| 100 Wh | 86042.06501 cal |
| 160 Wh | 137667.304 cal |
| 500 Wh | 430210.325 cal |
| 1000 Wh | 860420.6501 cal |
Where it's used
Watt-hours are used for battery capacity (phone ≈ 15 Wh; airline limit 100 Wh per power bank), while calories appear in chemistry and calorimetry. 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 calories are in 1 watt-hour?
1 Wh = 860.4206501 cal.
How do I convert watt-hours to calories?
Multiply the value in Wh by 860.4206501. For example, 15 Wh × 860.4206501 = 12906.30975 cal.
Is the Wh to cal conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
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, "calorie (thermochemical) (cal_th)".
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 Calories. Retrieved October 17, 2026, from https://scientificconverters.com/energy/watt-hours-to-calories/
IEEE
Scientific Converters, "Convert Watt-hours to Calories," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/watt-hours-to-calories/