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Energy
BTU to Watt-hours
Convert BTU (BTU) to watt-hours (Wh). Type a value below to see the result update instantly. Reference table and formula included.
Calculator
1 BTU = 0.293072 Wh
BTU to Watt-hours Conversion Table
Common values, ready to copy:
| BTU | watt-hours |
|---|---|
| 1 BTU | 0.293072 Wh |
| 2 BTU | 0.586144 Wh |
| 5 BTU | 1.4654 Wh |
| 10 BTU | 2.9307 Wh |
| 25 BTU | 7.3268 Wh |
| 50 BTU | 14.6536 Wh |
| 100 BTU | 29.3072 Wh |
| 1,000 BTU | 293.07 Wh |
Formula
watt-hours = BTU × 2.93072222e-1
Energy uses the SI joule. Food calories (kcal) are 1,000 small calories: 1 kcal = 4,184 J. 1 kWh = 3.6 MJ = 3,600,000 J. 1 BTU = 1,055.06 J.
About BTU and Watt-hours
BTU (BTU): British Thermal Unit; the energy to raise one pound of water by one degree Fahrenheit; defined as exactly 1,055.06 J. Common uses: US heating and air conditioning (a 24,000 BTU air conditioner cools roughly a 1,500 sq ft room), and US natural gas billing.
Watt-hours (Wh): The energy consumed by a 1-watt device in 1 hour; equals 3,600 joules. Common uses: Small battery capacities (laptop batteries are typically 40-100 Wh), and lighting energy use.
How the conversion works
Energy uses the SI joule. Food calories (kcal) are 1,000 small calories: 1 kcal = 4,184 J. 1 kWh = 3.6 MJ = 3,600,000 J. 1 BTU = 1,055.06 J.
The exact relationship is watt-hours = BTU × 2.93072222e-1, which the calculator at the top of this page applies in both directions. Type into either field and the other updates immediately.
When this conversion matters
Converting between BTU and watt-hours comes up wherever energy measurements move between systems — from one country's conventions to another's, from a scientific reference to a practical specification, or from one industry's working unit to another's. The calculator and reference table above cover the everyday range; for unusual values you can type any number into either field.