Power converter
Watts to BTU per Hour
Watts and BTU per Hour measure the same quantity in different unit systems. The relationship is 1 W = 3.412142 BTU/h, which gives 3.412142 BTU/h per W. Below you can convert any value, check a worked example and read the full chart.
Formula 1 W = 3.412142 BTU/h
Need the other direction? BTU per Hour to Watts.
How to convert Watts to BTU per Hour
The watt is one joule per second, the SI unit of power. One BTU per hour is about 0.293 watts, used for heating and cooling capacity.
To convert Watts to BTU per Hour, multiply the value in W by 3.412142. For example, 10 W × 3.412142 = 34.121416 BTU/h. This works because the ratio between the two units is constant for every value in power.
Worked examples
| W | BTU/h |
|---|---|
| 1 W | 3.412142 BTU/h |
| 2.5 W | 8.530354 BTU/h |
| 5 W | 17.060708 BTU/h |
| 10 W | 34.121416 BTU/h |
| 25 W | 85.303541 BTU/h |
| 50 W | 170.607082 BTU/h |
| 100 W | 341.214163 BTU/h |
Reverse conversion
| BTU/h | W |
|---|---|
| 1 BTU/h | 0.29307107 W |
| 5 BTU/h | 1.465355 W |
| 10 BTU/h | 2.930711 W |
| 25 BTU/h | 7.326777 W |
| 50 BTU/h | 14.653554 W |
| 100 BTU/h | 29.307107 W |
When this conversion is useful
This is the calculation you need when you are comparing an engine, a generator or an appliance across standards. Because the factor is fixed, you can use the same number for a single measurement or for a batch: 1,000 W is 3,412.14 BTU/h.
Is the conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Reference: BIPM SI Brochure and NIST SP 811. Last reviewed: 2026-11-01.
W to BTU/h conversion chart
The chart lists the most requested values. For a value that is not here, use the converter at the top of the page.
| Watts (W) | BTU per Hour (BTU/h) |
|---|---|
| 1 W | 3.412142 BTU/h |
| 2 W | 6.824283 BTU/h |
| 3 W | 10.236425 BTU/h |
| 4 W | 13.648567 BTU/h |
| 5 W | 17.060708 BTU/h |
| 6 W | 20.47285 BTU/h |
| 7 W | 23.884991 BTU/h |
| 8 W | 27.297133 BTU/h |
| 9 W | 30.709275 BTU/h |
| 10 W | 34.121416 BTU/h |
| 11 W | 37.533558 BTU/h |
| 12 W | 40.9457 BTU/h |
| 13 W | 44.357841 BTU/h |
| 14 W | 47.769983 BTU/h |
| 15 W | 51.182124 BTU/h |
| 16 W | 54.594266 BTU/h |
| 17 W | 58.006408 BTU/h |
| 18 W | 61.418549 BTU/h |
| 19 W | 64.830691 BTU/h |
| 20 W | 68.242833 BTU/h |
| 21 W | 71.654974 BTU/h |
| 22 W | 75.067116 BTU/h |
| 23 W | 78.479258 BTU/h |
| 24 W | 81.891399 BTU/h |
| 25 W | 85.303541 BTU/h |
| 26 W | 88.715682 BTU/h |
| 27 W | 92.127824 BTU/h |
| 28 W | 95.539966 BTU/h |
| 29 W | 98.952107 BTU/h |
| 30 W | 102.364249 BTU/h |
| 31 W | 105.776391 BTU/h |
| 32 W | 109.188532 BTU/h |
| 33 W | 112.600674 BTU/h |
| 34 W | 116.012816 BTU/h |
| 35 W | 119.424957 BTU/h |
| 36 W | 122.837099 BTU/h |
| 37 W | 126.24924 BTU/h |
| 38 W | 129.661382 BTU/h |
| 39 W | 133.073524 BTU/h |
| 40 W | 136.485665 BTU/h |
| 41 W | 139.897807 BTU/h |
| 42 W | 143.309949 BTU/h |
| 43 W | 146.72209 BTU/h |
| 44 W | 150.134232 BTU/h |
| 45 W | 153.546373 BTU/h |
| 46 W | 156.958515 BTU/h |
| 47 W | 160.370657 BTU/h |
| 48 W | 163.782798 BTU/h |
| 49 W | 167.19494 BTU/h |
| 50 W | 170.607082 BTU/h |
| 60 W | 204.728498 BTU/h |
| 70 W | 238.849914 BTU/h |
| 80 W | 272.971331 BTU/h |
| 90 W | 307.092747 BTU/h |
| 100 W | 341.214163 BTU/h |
Frequently asked questions
How many BTU per Hour are in 1 Watts?
1 W equals 3.412142 BTU/h.
How do I convert Watts to BTU per Hour?
Multiply the W value by 3.412142. Example: 25 W = 85.303541 BTU/h.
What is 2.5 W in BTU/h?
2.5 W = 8.530354 BTU/h.
Is the W to BTU/h conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Does the calculator work offline?
Yes. The conversion runs in your browser with JavaScript, so it works after the page has loaded, even without a connection.