Convert BTU to joules

1 BTU=1,055.06J

Use the converter below to change any BTU value into joules instantly — with formula, conversion table, and real-world examples.

You have

Equals

1,055.06

Conversion formula

Forward

joules = BTU × 1,055.06

Reverse

BTU = joules × 0.0009478

Example: 10 BTU × 1,055.06 = 10,550.56 J.

About both units

From

British Thermal Unit

BTU

The British Thermal Unit equals approximately 1055 joules — the energy to raise 1 pound of water by 1 °F. Used for HVAC, heating, and air-conditioning capacity in the US. A 9000 BTU/h AC is a small room unit.

Real-world: Window AC: 5000–12,000 BTU/h. Central AC: 24,000–60,000 BTU/h. Home furnace: 60,000–100,000 BTU/h.

Read full british thermal unit reference →

Joule

The joule is the SI unit of energy, work and heat. Defined as one newton-metre or one watt-second. Named after James Prescott Joule who demonstrated the mechanical equivalent of heat. Lifting a 100 g apple 1 metre requires about 1 J.

Real-world: Lifting a 100 g apple 1 m: ≈ 1 J. 100 kcal snack: 418,400 J. Hand grenade: ~650 kJ.

Read full joule reference →

British Thermal Unit to Joule conversion table

Common BTU to joules values for quick reference.

British Thermal Unit (BTU)	Joule (J)
1 BTU	1,055.06 J
10 BTU	10,550.56 J
100 BTU	105,505.58 J
500 BTU	527,527.92 J
1,000 BTU	1,055,055.85 J
5,000 BTU	5,275,279.25 J
10,000 BTU	10,550,558.5 J
50,000 BTU	52,752,792.5 J
100,000 BTU	105,505,585 J
500,000 BTU	527,527,925 J

Tips & common mistakes

Quick tips

1 BTU = 1055.06 J = 0.293 Wh.
BTU/h (power) and BTU (energy) are different — don't confuse.
Tons of refrigeration: 12,000 BTU/h = 1 ton AC.

Avoid these

Confusing BTU and BTU/h — energy vs power.
Using kcal when BTU is requested in HVAC specs.
Treating all BTUs as exact — definitions vary (IT, thermochemical, etc.).

Frequently asked questions

How many joules in a british thermal unit?

One british thermal unit equals 1,055.06 joules.

How do I convert BTU to joules?

Multiply the british thermal unit value by 1,055.06 to get the equivalent in joules.

What is 100 BTU in joules?

100 BTU equals 105,505.58 joules.

Is a british thermal unit bigger than a joule?

Yes. 1 british thermal unit equals 1,055.06 joules, so one british thermal unit is larger.

How to convert BTU to joules without a calculator?

Multiply by 1,055.06 for a quick estimate; use a calculator for precise results.

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