Watts to BTU/hr Converter
Convert watt to btu per hour instantly. 1 W = 3.412141635 BTU/hr, worked steps and a full reference table.
How to use it
- Type the value in watt — the result updates as you type.
- Use Swap to flip the direction, or change either dropdown to convert between any two units.
- Click the result to copy it. The URL updates too, so you can bookmark or share the exact conversion.
Examples
| 1 W | 3.412141635 BTU/hr |
| 5 W | 17.06070818 BTU/hr |
| 10 W | 34.12141635 BTU/hr |
| 100 W | 341.2141635 BTU/hr |
One watt equals 3.4121416 btu per hours (BTU/hr). To convert watts to btu per hours, multiply by 3.4121416; to go back the other way, multiply by 0.29307107 instead.
The converter above does it as you type and shows the working underneath, so you can check the arithmetic rather than take the number on trust.
What watts and btu per hours actually measure
Watt (W) — The watt is the SI unit of power — one joule per second. Light bulbs, appliances, audio equipment and solar panels.
BTU per hour (BTU/hr) — BTU per hour measures heat flow — one British thermal unit each hour. Air conditioning, heating and boiler ratings.
Watts to BTU/hr conversion table
The most common values, worked out in advance. Anything not listed can be typed straight into the converter.
| W | BTU/hr |
|---|---|
| 1 W | 3.4121416 BTU/hr |
| 2 W | 6.8242833 BTU/hr |
| 5 W | 17.060708 BTU/hr |
| 10 W | 34.121416 BTU/hr |
| 25 W | 85.303541 BTU/hr |
| 50 W | 170.60708 BTU/hr |
| 100 W | 341.21416 BTU/hr |
How to convert watts to btu per hours by hand
Multiply the number of watts by 3.4121416.
For example, 25 W × 3.4121416 = 85.303541 BTU/hr.
Going the other way, divide by 3.4121416 — or multiply by 0.29307107, which is the same thing and easier to do in your head.
Everything runs in your browser
There is no server involved in the calculation. The numbers you type never leave your device, nothing is logged, and the page keeps working with no connection once it has loaded. That is not a marketing line — it is simply how the tool is built, because a calculation like this has no reason to touch a network.
Questions people ask
How many BTU/hr are in 1 W?
1 W equals exactly 3.412141635 BTU/hr. Multiply any value in watt by 3.412141635 to get btu per hour.
Is anything uploaded to a server?
No. The whole calculation happens in your browser. Nothing is sent anywhere, and the page keeps working offline once loaded.
Last updated 18 August 2026