Convert Watts to Kilocalories per Hour
1 watt (W) equals 0.8598452279 kilocalories per hour (kcal/h).
1 W = 0.8598452279 kcal/h
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk watt to kilocalorie per hour converter to paste a column from Excel.
How to Convert Watt to Kilocalorie per Hour
- 1 W = 0.8598452279 kcal/h
- 1 kcal/h = 1.163 W
- Example: convert 15 W to kcal/h: 15 W = 15 × 0.8598452279 kcal/h = 12.89767842 kcal/h
Reference conditions. kcal/h: Uses the International Table kilocalorie (4186.8 J), the convention in heating and HVAC: 1 kcal/h = 1.163 W.
Formula
kcal/h = W × 0.859845227859
or kcal/h = W ÷ 1.163
Derivation from SI units:
- 1 W = 1 J/s = 1 kg·m²·s⁻³
- 1 kcal_IT/h = 4186.8 J ÷ 3600 s = 1.163 W (exact)
Both units are defined exactly, so the factor is exact. Watt definition: watt; Kilocalorie per Hour definition: kilocalorie per hour.
Worked examples
- 1000 W is 859.8452279 kcal/h.
1000 W × 0.8598452279 = 859.8452279 kcal/h - A 2500 W heater is 2149.61307 kcal/h.
2500 W × 0.8598452279 = 2149.61307 kcal/h
Watt to Kilocalorie per Hour conversion table
| Watts (W) | Kilocalories per Hour (kcal/h) |
|---|---|
| 1 W | 0.8598452279 kcal/h |
| 5 W | 4.299226139 kcal/h |
| 10 W | 8.598452279 kcal/h |
| 40 W | 34.39380911 kcal/h |
| 60 W | 51.59071367 kcal/h |
| 100 W | 85.98452279 kcal/h |
| 250 W | 214.961307 kcal/h |
| 500 W | 429.9226139 kcal/h |
| 746 W | 641.44454 kcal/h |
| 1000 W | 859.8452279 kcal/h |
| 1500 W | 1289.767842 kcal/h |
| 2000 W | 1719.690456 kcal/h |
| 3500 W | 3009.458298 kcal/h |
| 5000 W | 4299.226139 kcal/h |
| 10000 W | 8598.452279 kcal/h |
Where it's used
Watt ratings are converted to kcal/h for comparison with older European and Asian heating data.
Watt to other power units
| Conversion | 1 W equals |
|---|---|
| watt to milliwatt | 1000 mW |
| watt to kilowatt | 0.001 kW |
| watt to megawatt | 0.000001 MW |
| watt to horsepower | 0.00134102209 hp |
| watt to metric horsepower | 0.001359621617 PS |
| watt to BTU per hour | 3.412141633 BTU/h |
| watt to refrigeration ton | 0.0002843451361 TR |
| watt to kilocalorie per hour | 0.8598452279 kcal/h |
| watt to foot-pound per second | 0.7375621493 ft·lbf/s |
Frequently asked questions
How many kcal/h is 1 kW?
1 kW = 859.845 kcal/h.
How many kilocalories per hour are in 1 watt?
1 W = 0.8598452279 kcal/h.
How do I convert watts to kilocalories per hour?
Multiply the value in W by 0.8598452279, or divide it by 1.163. For example, 15 W × 0.8598452279 = 12.89767842 kcal/h.
Is the W to kcal/h 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
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4, coherent derived units with special names.
- 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_IT" with hour.
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 Watts to Kilocalories per Hour. Retrieved October 17, 2026, from https://scientificconverters.com/power/watts-to-kilocalories-per-hour/
IEEE
Scientific Converters, "Convert Watts to Kilocalories per Hour," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/power/watts-to-kilocalories-per-hour/