Convert joules to BTU

1 J=0.0009478BTU

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

You have

Equals

0.00094782

Conversion formula

Forward

BTU = joules × 0.0009478

Reverse

joules = BTU × 1,055.06

Example: 10 J × 0.0009478 = 0.009478 BTU.

About both units

From

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

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 to British Thermal Unit conversion table

Common joules to BTU values for quick reference.

Joule (J)	British Thermal Unit (BTU)
1 J	0.0009478 BTU
10 J	0.009478 BTU
100 J	0.09478 BTU
500 J	0.4739 BTU
1,000 J	0.9478 BTU
5,000 J	4.73909 BTU
10,000 J	9.47817 BTU
50,000 J	47.3909 BTU
100,000 J	94.7817 BTU
500,000 J	473.909 BTU

Tips & common mistakes

Quick tips

1 J = 1 N·m = 1 W·s.
1 kWh = 3,600,000 J (3.6 MJ).
For nutrition 1 kcal = 4.184 kJ.

Avoid these

Confusing joule (energy) with newton (force).
Mixing joule with watt — watt is joule per second.
Using kJ when labels call for kcal on US nutrition.

Frequently asked questions

How many BTU in a joule?

One joule equals 0.0009478 BTU.

How do I convert joules to BTU?

Multiply the joule value by 0.0009478 to get the equivalent in BTU.

What is 100 joules in BTU?

100 joules equals 0.09478 BTU.

Is a joule bigger than a british thermal unit?

No. 1 joule equals 0.0009478 BTU, so one joule is smaller.

How to convert joules to BTU without a calculator?

Multiply by 0 for a quick estimate; use a calculator for precise results.

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