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Convert BTU to joules
Instant, accurate BTU → J conversion with a live converter, table and formula.
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1 BTU = 1055.06 joules
1 joule = 0.000947817 BTU
BTU to joules table
| BTU (BTU) | joules (J) |
|---|---|
| 0.5 | 527.528 |
| 1 | 1055.06 |
| 2 | 2110.11 |
| 5 | 5275.28 |
| 10 | 10550.56 |
| 20 | 21101.12 |
| 50 | 52752.79 |
| 100 | 105505.59 |
| 500 | 527527.93 |
| 1000 | 1055055.85 |
Formula
joules = BTU × 1055.06.
Example
10 BTU = 10550.56 joules.
What is a BTU?
A BTU is the energy to heat 1 lb of water by 1°F (about 1,055 J).
What is a joule?
The joule (J) is the SI unit of energy.
Real-world reference points
A food Calorie is a kilocalorie: an apple is ~52 kcal, a daily diet ~2,000 kcal (~8.4 MJ).
| Reference | BTU | joules |
|---|---|---|
| AA battery | 14.59 BTU | 15,390 J |
| Smartphone battery (13 Wh) | 44.36 BTU | 46,800 J |
| Apple (52 kcal) | 206 BTU | 218,000 J |
| Daily diet (2,000 kcal) | 7,931 BTU | 8,370,000 J |
| 1 kWh (unit of electricity) | 3,412 BTU | 3,600,000 J |
Mistakes to avoid with energy conversions
- Food 'Calories' are kilocalories — mixing cal and kcal creates 1000× errors.
- Confusing kWh (energy) with kW (power) on bills and appliance labels.
- Comparing battery mAh across different voltages — energy needs Wh, not mAh alone.
Frequently asked questions
How many joules in a BTU?+
1 BTU = 1055.06 joules.
How do I convert BTU to joules?+
Enter the value in the BTU box above and the joules value appears instantly. You can also type in the joules box to convert the other way.
Is this BTU to J converter free?+
Yes — it is 100% free, needs no sign-up, and runs entirely in your browser.