British thermal units to watt-hours
Type a value in British thermal units to see it in watt-hours straight away, or type in the second box to convert back.
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How to use it
- Type the value in the British thermal units box.
- Read the result in watt-hours as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
Wh = BTU × 0.2930710702
Multiply the value in British thermal units by 0.2930710702 to get watt-hours.
Example
To convert 25 BTU to watt-hours: 25 × 0.2930710702 = 7.32678 Wh.
Conversion table
| British thermal units (BTU) | Watt-hours (Wh) |
|---|---|
| 1 | 0.293071 |
| 2 | 0.586142 |
| 3 | 0.879213 |
| 5 | 1.46536 |
| 10 | 2.93071 |
| 20 | 5.86142 |
| 25 | 7.32678 |
| 50 | 14.6536 |
| 100 | 29.3071 |
| 250 | 73.2678 |
| 500 | 146.536 |
| 1,000 | 293.071 |
About the units
- British thermal unit
- The imperial unit of heat, using the International Table definition of exactly 1055.05585262 joules. Seen in air conditioner and heater ratings.
- Watt-hour
- The energy used by a one watt device in one hour, exactly 3600 joules. Common for battery and power bank capacity.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many watt-hours are in one British thermal unit?
1 BTU = 0.293071 Wh exactly.
How do I convert British thermal units to watt-hours?
Use Wh = BTU × 0.2930710702. For example, 25 BTU = 7.32678 Wh.
How many British thermal units are in one watt-hour?
1 Wh = 3.41214 BTU.
Which calorie do these converters use?
The thermochemical calorie, exactly 4.184 joules, the factor many countries use to turn kcal into kJ on food labels. The International Table calorie is 4.1868 joules, less than 0.07% larger.
What is the difference between kW and kWh?
A kilowatt is a unit of power, the rate of using energy, while a kilowatt-hour is an amount of energy. A 2 kW heater running for three hours uses 6 kWh.