Watt-Hours to BTU Converter
Convert watt-hours to British thermal units — one watt-hour is 3.412 BTU. Results update as you type; exact factors shown.
One watt-hour is 3.4121 British thermal units — see the exact factor, not a rounded rule of thumb.
How the watt-hours to btu converter works
Energy converts through the joule. A thermochemical calorie is exactly 4.184 J, so a food Calorie (kcal) is 4.184 kJ. A kilowatt-hour is exactly 3.6 MJ. A BTU is 1,055.056 J and a US therm is 100,000 BTU.
The US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common energy conversions
| From | To | Units |
|---|---|---|
| 1 Wh | 3.4121 BTU | watt-hour to British thermal units |
| 5 Wh | 17.0607 BTU | watt-hours to British thermal units |
| 10 Wh | 34.1214 BTU | watt-hours to British thermal units |
| 50 Wh | 170.6071 BTU | watt-hours to British thermal units |
| 100 Wh | 341.2142 BTU | watt-hours to British thermal units |
| 293 Wh | 999.7575 BTU | watt-hours to British thermal units |
| 500 Wh | 1,706.0708 BTU | watt-hours to British thermal units |
| 1,000 Wh | 3,412.1416 BTU | watt-hours to British thermal units |
| 2,000 Wh | 6,824.2833 BTU | watt-hours to British thermal units |
| 5,000 Wh | 17,060.7082 BTU | watt-hours to British thermal units |
| 10,000 Wh | 34,121.4163 BTU | watt-hours to British thermal units |
| 100,000 Wh | 341,214.1633 BTU | watt-hours to British thermal units |
Units in this converter and their exact factors
| Unit | Symbol | One unit in joules |
|---|---|---|
| joule | J | 1 joule |
| kilojoule | kJ | 1,000 joule |
| megajoule | MJ | 1,000,000 joule |
| calorie (thermochemical) | cal | 4.184 joule |
| kilocalorie (food Calorie) | kcal | 4,184 joule |
| watt-hour | Wh | 3,600 joule |
| kilowatt-hour | kWh | 3,600,000 joule |
| British thermal unit | BTU | 1,055.05585262 joule |
| therm (US) | thm | 105,505,585.262 joule |
| foot-pound | ft·lb | 1.3558179483 joule |
FAQFrequently asked questions about energy conversion
How many BTU in a watt-hour?
3.412 BTU.
What is 293 Wh?
About 1,000 BTU.
What is 1 kWh in BTU?
3,412 BTU.
Why do air conditioners mix the two?
Because the cooling output is rated in BTU by US convention while the electricity it draws is metered in watt-hours.
Which is bigger?
A watt-hour, by a factor of about 3.4.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.