Convert BTU to Kilowatt-Hours
BTU to kilowatt-hours is the conversion you need when a heating or cooling rating is in British thermal units but you want it in the kilowatt-hours your electric bill uses. One BTU is approximately 0.000293071 kilowatt-hours, so the kilowatt-hour number always comes out very small.
British thermal units to Kilowatt-hours conversion table
| British thermal units (BTU) | Kilowatt-hours (kWh) |
|---|---|
| 1 | 0.000293 |
| 2 | 0.000586 |
| 3 | 0.000879 |
| 5 | 0.001465 |
| 10 | 0.002931 |
| 20 | 0.005861 |
| 50 | 0.014654 |
| 100 | 0.029307 |
| 500 | 0.146536 |
| 1,000 | 0.293071 |
The formula
To convert BTU to kilowatt-hours, multiply the number of BTU by 0.000293071 (about 0.0002930710701722222):
kilowatt-hours = BTU × 0.000293071
A worked example
Say you have 10,000 BTU and want it in kilowatt-hours:
10,000 × 0.0002930710701722222 = 2.9307107 kWh
So 10,000 BTU is about 2.93 kilowatt-hours.
Why it's an approximation
The BTU and the kilowatt-hour come from different starting points — one from warming water, the other built up from watts and hours — and they don't divide evenly into each other. That's why the factor 0.0002930710701722222 doesn't settle on a clean value. Rounded to 0.000293071 it's plenty accurate for everyday use, and it stays approximate no matter how many decimals you keep.
When you'll use it
Estimating what an air conditioner or heater rated in BTU would add to an electric bill measured in kilowatt-hours, comparing a gas appliance's BTU output against an electric one's kilowatt-hours, or sizing energy use where the rest of the numbers are already in kWh.
Frequently asked questions
How many kilowatt-hours are in a BTU?
Approximately 0.000293071 kilowatt-hours. It's a rounded figure — the exact value runs on past those decimal places, so 0.000293071 is the practical number to use.
Why is the kilowatt-hour number so tiny?
Because a kilowatt-hour is a large amount of energy and a single BTU is a small one. It takes thousands of BTU to add up to one kilowatt-hour, so the per-BTU figure is a small fraction.
Is the BTU to kilowatt-hours conversion exact?
No. The BTU and the kilowatt-hour don't divide evenly, so the factor 0.000293071 is rounded for everyday use. More decimal places give you more precision if you need it.