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British Thermal Units to Joules Converter

Convert British thermal units (IT) (Btu) to joules (watt-seconds) (J), 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
1,055.05585262 J
kilojoules
1.05505585262 kJ
megajoules
0.00105505585262 MJ
gigajoules
1.05505585262 × 10⁻⁶ GJ
calories (thermochemical)
252.164400722 cal
kilocalories (food Calories)
0.252164400722 kcal
megacalories
0.000252164400722 Mcal
watt-hours
0.293071070172 Wh
kilowatt-hours
0.000293071070172 kWh
megawatt-hours
2.93071070172 × 10⁻⁷ MWh
million Btu
1 × 10⁻⁶ MMBtu
therms (100,000 Btu)
1 × 10⁻⁵ thm
quads (10¹⁵ Btu)
1 × 10⁻¹⁵ quad
electronvolts
6.58514067819 × 10²¹ eV
kiloelectronvolts
6.58514067819 × 10¹⁸ keV
megaelectronvolts
6.58514067819 × 10¹⁵ MeV

1 Btu = 1,055.05585262 J

Show the working
  1. 1 Btu = 1055.05585262 J
  2. 1 × 1055.05585262 = 1055.05585262 J

How to convert british thermal units to joules

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

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

Worked example:

1 Btu = 1055.05585262 J
5 × 1055.05585262 = 5275.2792631 J

British Thermal Units to joules table

British Thermal UnitsJoules
1 Btu1,055.05585262 J
2 Btu2,110.11170524 J
3 Btu3,165.16755786 J
4 Btu4,220.22341048 J
5 Btu5,275.2792631 J
6 Btu6,330.33511572 J
7 Btu7,385.39096834 J
8 Btu8,440.44682096 J
9 Btu9,495.50267358 J
10 Btu10,550.5585262 J
15 Btu15,825.8377893 J
20 Btu21,101.1170524 J
25 Btu26,376.3963155 J
30 Btu31,651.6755786 J
40 Btu42,202.2341048 J
50 Btu52,752.792631 J
75 Btu79,129.1889465 J
100 Btu105,505.585262 J
250 Btu263,763.963155 J
500 Btu527,527.92631 J
1000 Btu1,055,055.85262 J

About the units

British Thermal Units (Btu)
British thermal units (IT), a US customary unit. Definition: NIST SP 811 Appendix B.8, factors for units listed alphabetically.
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).

Formula version 0.1.0Reviewed