British Thermal Units to Watt-hours Converter
1 British thermal unit ≈ 0.29307107 watt-hours
Several BTU definitions exist. This converter uses the International Table BTU, the one used by HVAC equipment ratings.
1 British thermal unit equals 0.293071 watt-hours
How to convert British thermal units to watt-hours
Calories here are thermochemical (4.184 J), while BTU uses the International Table definition. A kilowatt-hour is energy (3.6 MJ), not power; a food Calorie is a kilocalorie.
Wh = BTU × 0.2930710702One British thermal unit is 0.2930710702 watt-hours, so a single multiplication converts any value.
2.93071 Wh ≈ 10 × 0.2930710702Several BTU definitions exist. This converter uses the International Table BTU, the one used by HVAC equipment ratings.
British thermal units to watt-hours conversion table
Common values in British thermal units, converted to watt-hours.
| British thermal units (BTU) | Watt-hours (Wh) |
|---|---|
| 1 | 0.29307107 |
| 2 | 0.58614214 |
| 3 | 0.87921321 |
| 4 | 1.1722843 |
| 5 | 1.4653554 |
| 10 | 2.9307107 |
| 20 | 5.8614214 |
| 25 | 7.3267768 |
| 50 | 14.653554 |
| 100 | 29.307107 |
| 250 | 73.267768 |
| 500 | 146.53554 |
| 1,000 | 293.07107 |
About these units
British thermal unitBTU
The International Table BTU: 1,055.05585262 joules. The US heating and cooling unit.
Reference: NIST Special Publication 811.
watt-hourWh
One watt sustained for one hour: exactly 3,600 joules.
Sources and precision
Table results are rounded to 8 significant digits; formula constants may be rounded to 10. Worked example answers use 6 significant digits. The converter starts at 6 significant digits and lets you change display precision. Calculations use the stored factors without intermediate rounding. Exact unit definitions do not make an input measurement more precise; conventional and measured factors follow the assumptions stated here.