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Joules to British Thermal Units Converter

Convert joules (watt-seconds) (J) to British thermal units (IT) (Btu), with the formula, a conversion table and exact factors.

Change the values and press Calculate to work out your own figures.

Enter an amount of energy, choose its unit and the unit you want. The answer is exact until it is shown, and the same value appears in every other unit.

A number, fraction (3/8), mixed number (1 1/2), scientific notation (2.5e6) or a simple sum such as 2*3.
The unit you want the answer in. Swap exchanges the two units.
Result
0.000947817120313 Btu
kilojoules
0.001 kJ
megajoules
1 × 10⁻⁶ MJ
gigajoules
1 × 10⁻⁹ GJ
calories (thermochemical)
0.239005736138 cal
kilocalories (food Calories)
0.000239005736138 kcal
megacalories
2.39005736138 × 10⁻⁷ Mcal
watt-hours
0.000277777777778 Wh
kilowatt-hours
2.77777777778 × 10⁻⁷ kWh
megawatt-hours
2.77777777778 × 10⁻¹⁰ MWh
million Btu
9.47817120313 × 10⁻¹⁰ MMBtu
therms (100,000 Btu)
9.47817120313 × 10⁻⁹ thm
quads (10¹⁵ Btu)
9.47817120313 × 10⁻¹⁹ quad
electronvolts
6.24150907446 × 10¹⁸ eV
kiloelectronvolts
6.24150907446 × 10¹⁵ keV
megaelectronvolts
6,241,509,074,460 MeV

1 J = 0.000947817120313 Btu

Show the working
  1. 1 J = 0.000947817120313 Btu
  2. 1 × 0.000947817120313 = 0.000947817120313 Btu

How to convert joules to british thermal units

1 J = 0.000947817120313 Btu, so multiply by 0.000947817120313 to go from joules (watt-seconds) to British thermal units (IT). Going the other way, 1 Btu = 1,055.05585262 J.

Btu = J × 0.000947817120313
J = Btu × 1,055.05585262

Worked example:

1 J = 0.000947817120313 Btu
5 × 0.000947817120313 = 0.00473908560157 Btu

Joules to british thermal units table

JoulesBritish Thermal Units
1 J0.000947817120313 Btu
2 J0.00189563424063 Btu
3 J0.00284345136094 Btu
4 J0.00379126848125 Btu
5 J0.00473908560157 Btu
6 J0.00568690272188 Btu
7 J0.00663471984219 Btu
8 J0.00758253696251 Btu
9 J0.00853035408282 Btu
10 J0.00947817120313 Btu
15 J0.0142172568047 Btu
20 J0.0189563424063 Btu
25 J0.0236954280078 Btu
30 J0.0284345136094 Btu
40 J0.0379126848125 Btu
50 J0.0473908560157 Btu
75 J0.0710862840235 Btu
100 J0.0947817120313 Btu
250 J0.236954280078 Btu
500 J0.473908560157 Btu
1000 J0.947817120313 Btu

About the units

Joules (J)
Joules (watt-seconds), a metric unit. Definition: BIPM SI Brochure, 9th edition (SI units, prefixes and units accepted for use with the SI).
British Thermal Units (Btu)
British thermal units (IT), a US customary unit. Definition: NIST SP 811 Appendix B.8, factors for units listed alphabetically.

Formula version 0.1.0Reviewed