Convert Watts to BTU per Hour
1 watt (W) equals 3.412141633 BTU per hour (BTU/h).
1 W = 3.412141633 BTU/h
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk watt to BTU per hour converter to paste a column from Excel.
How to Convert Watt to BTU per Hour
- 1 W = 3.412141633 BTU/h
- 1 BTU/h = 0.2930710702 W
- Example: convert 15 W to BTU/h: 15 W = 15 × 3.412141633 BTU/h = 51.1821245 BTU/h
Formula
BTU/h = W × 3.412141633128
Derivation from SI units:
- 1 W = 1 J/s = 1 kg·m²·s⁻³
- 1 BTU/h = 1055.05585262 J ÷ 3600 s = 0.29307107 W
Both units are defined exactly, so the factor is exact. Watt definition: watt; BTU per Hour definition: BTU per hour.
Worked examples
- A 1500 W space heater produces 5118.21245 BTU/h.
1500 W × 3.412141633 = 5118.21245 BTU/h - 1000 W is 3412.141633 BTU/h.
1000 W × 3.412141633 = 3412.141633 BTU/h
Watt to BTU per Hour conversion table
| Watts (W) | BTU per Hour (BTU/h) |
|---|---|
| 1 W | 3.412141633 BTU/h |
| 5 W | 17.06070817 BTU/h |
| 10 W | 34.12141633 BTU/h |
| 40 W | 136.4856653 BTU/h |
| 60 W | 204.728498 BTU/h |
| 100 W | 341.2141633 BTU/h |
| 250 W | 853.0354083 BTU/h |
| 500 W | 1706.070817 BTU/h |
| 746 W | 2545.457658 BTU/h |
| 1000 W | 3412.141633 BTU/h |
| 1500 W | 5118.21245 BTU/h |
| 2000 W | 6824.283266 BTU/h |
| 3500 W | 11942.49572 BTU/h |
| 5000 W | 17060.70817 BTU/h |
| 10000 W | 34121.41633 BTU/h |
Where it's used
Electrical loads and heater ratings in watts are converted to BTU/h for US HVAC load calculations. 1 W is about 3.412 BTU/h.
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 BTU/h is 1 watt?
1 W = 3.412141633 BTU/h.
How many BTU per hour are in 1 watt?
1 W = 3.412141633 BTU/h.
How do I convert watts to BTU per hour?
Multiply the value in W by 3.412141633. For example, 15 W × 3.412141633 = 51.1821245 BTU/h.
Is the W to BTU/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, "British thermal unit_IT per 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 BTU per Hour. Retrieved October 17, 2026, from https://scientificconverters.com/power/watts-to-btu-per-hour/
IEEE
Scientific Converters, "Convert Watts to BTU per Hour," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/power/watts-to-btu-per-hour/