Convert Joules to BTU
Convert Joules to BTU instantly. 1 Joule (J) equals 0.0009478 BTU (BTU).
Joules to BTU conversion table
| Joules (J) | BTU (BTU) |
|---|---|
| 1 J | 0.0009478 BTU |
| 2 J | 0.001896 BTU |
| 3 J | 0.002843 BTU |
| 5 J | 0.004739 BTU |
| 10 J | 0.009478 BTU |
| 20 J | 0.01896 BTU |
| 50 J | 0.04739 BTU |
| 100 J | 0.09478 BTU |
| 500 J | 0.4739 BTU |
| 1,000 J | 0.9478 BTU |
1 Joule = 0.0009478 BTU · multiply Joules by 0.0009478
About converting Joules to BTU
Joules (J) and BTU (BTU) are both units of energy, so converting between them is a single multiplication: multiply your Joules figure by 0.0009478. Ten Joules comes to 0.009478 BTU, and a hundred works out at 0.09478 BTU.
Rule of thumb: going from Joules to BTU divides, so the figure always shrinks — it takes about 1,055.06 Joules to make a single BTU. If your answer came out bigger, you have the conversion the wrong way round.
What is a Joule?
The joule is the SI unit of energy and the reference every other energy unit here is defined against. One joule is one newton acting over one metre — push with a newton of force, move a metre, and you have spent a joule. It is named after James Prescott Joule, whose painstaking experiments established that heat and mechanical work are the same thing, measurable in the same units. That result sounds obvious now and was foundational then: it collapsed heat, motion and work into a single quantity called energy, which is why one unit can serve food, electricity, explosives and engines alike.
What is a BTU?
The BTU is the heat needed to raise one pound of water by one degree Fahrenheit — and there is no single BTU. Water takes slightly different amounts of heat to warm depending on the temperature it starts from, so several definitions exist (thermochemical, International Table, 39 °F, 59 °F, 60 °F and others), differing from one another by a fraction of a percent. This converter uses one common value, so treat the result as convention-dependent rather than absolute. In the US it is the unit of heating and cooling capacity, though air conditioners are really rated in BTU per hour and the "per hour" is routinely dropped in marketing.
To put both in perspective: lifting an apple one metre takes about a joule, while a wooden kitchen match releases roughly one BTU.
The converter above updates as you type, and the table lists common values for quick reference. Need the opposite direction? Use the BTU to Joules converter, or browse all Energy converters.
Frequently asked questions
How many BTU are in one Joule?
There are 0.0009478 BTU in one Joule.
How do I convert Joules to BTU?
Multiply the number of Joules by 0.0009478. For example, 10 Joules = 0.009478 BTU.
What is 100 Joules in BTU?
100 Joules is equal to 0.09478 BTU.
How do I convert BTU to Joules?
Multiply the BTU value by 1,055.06 (or divide by 0.0009478).
Is this Joules to BTU conversion exact?
The figure is accurate to the precision shown. 1 Joule = 0.0009478 BTU is rounded for readability, so for engineering or scientific work carry more decimal places than the table displays.
What is a Joule?
The joule is the SI unit of energy and the reference every other energy unit here is defined against. One joule is one newton acting over one metre — push with a newton of force, move a metre, and you have spent a joule. It is named after James Prescott Joule, whose painstaking experiments established that heat and mechanical work are the same thing, measurable in the same units. That result sounds obvious now and was foundational then: it collapsed heat, motion and work into a single quantity called energy, which is why one unit can serve food, electricity, explosives and engines alike.
What is a BTU?
The BTU is the heat needed to raise one pound of water by one degree Fahrenheit — and there is no single BTU. Water takes slightly different amounts of heat to warm depending on the temperature it starts from, so several definitions exist (thermochemical, International Table, 39 °F, 59 °F, 60 °F and others), differing from one another by a fraction of a percent. This converter uses one common value, so treat the result as convention-dependent rather than absolute. In the US it is the unit of heating and cooling capacity, though air conditioners are really rated in BTU per hour and the "per hour" is routinely dropped in marketing.