Home› Conversions› Energy› Joules to BTU
Energy
Joules to BTU
Convert joules (J) to BTU (BTU). Type a value below to see the result update instantly. Reference table and formula included.
Calculator
1 J = 0.000948 BTU
Joules to BTU Conversion Table
Common values, ready to copy:
| joules | BTU |
|---|---|
| 1 J | 0.000948 BTU |
| 2 J | 0.001896 BTU |
| 5 J | 0.004739 BTU |
| 10 J | 0.009478 BTU |
| 25 J | 0.023695 BTU |
| 50 J | 0.047391 BTU |
| 100 J | 0.094781 BTU |
| 1,000 J | 0.947813 BTU |
Formula
BTU = joules × 9.47813394e-4
Energy uses the SI joule. Food calories (kcal) are 1,000 small calories: 1 kcal = 4,184 J. 1 kWh = 3.6 MJ = 3,600,000 J. 1 BTU = 1,055.06 J.
About Joules and BTU
Joules (J): The SI unit of energy; named for James Prescott Joule, whose 19th-century experiments established the equivalence of mechanical work and heat. Common uses: Physics calculations, food calorie labeling in metric countries (kilojoules), battery capacity, and chemistry.
BTU (BTU): British Thermal Unit; the energy to raise one pound of water by one degree Fahrenheit; defined as exactly 1,055.06 J. Common uses: US heating and air conditioning (a 24,000 BTU air conditioner cools roughly a 1,500 sq ft room), and US natural gas billing.
How the conversion works
Energy uses the SI joule. Food calories (kcal) are 1,000 small calories: 1 kcal = 4,184 J. 1 kWh = 3.6 MJ = 3,600,000 J. 1 BTU = 1,055.06 J.
The exact relationship is BTU = joules × 9.47813394e-4, which the calculator at the top of this page applies in both directions. Type into either field and the other updates immediately.
When this conversion matters
Converting between joules and BTU comes up wherever energy measurements move between systems — from one country's conventions to another's, from a scientific reference to a practical specification, or from one industry's working unit to another's. The calculator and reference table above cover the everyday range; for unusual values you can type any number into either field.