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Joules to Calories Converter

Convert joules (watt-seconds) (J) to calories (thermochemical) (cal), 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
0.239005736138 cal
kilojoules
0.001 kJ
megajoules
1 × 10⁻⁶ MJ
gigajoules
1 × 10⁻⁹ GJ
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
British thermal units (IT)
0.000947817120313 Btu
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 = 0.239005736138 cal

Show the working
  1. 1 J = 0.239005736138 cal
  2. 1 × 0.239005736138 = 0.239005736138 cal

How to convert joules to calories

1 J = 0.239005736138 cal, so multiply by 0.239005736138 to go from joules (watt-seconds) to calories (thermochemical). Going the other way, 1 cal = 4.184 J.

cal = J × 0.239005736138
J = cal × 4.184

Worked example:

1 J = 0.239005736138 cal
5 × 0.239005736138 = 1.19502868069 cal

Joules to calories table

JoulesCalories
1 J0.239005736138 cal
2 J0.478011472275 cal
3 J0.717017208413 cal
4 J0.956022944551 cal
5 J1.19502868069 cal
6 J1.43403441683 cal
7 J1.67304015296 cal
8 J1.9120458891 cal
9 J2.15105162524 cal
10 J2.39005736138 cal
15 J3.58508604207 cal
20 J4.78011472275 cal
25 J5.97514340344 cal
30 J7.17017208413 cal
40 J9.56022944551 cal
50 J11.9502868069 cal
75 J17.9254302103 cal
100 J23.9005736138 cal
250 J59.7514340344 cal
500 J119.502868069 cal
1000 J239.005736138 cal

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).
Calories (cal)
Calories (thermochemical), a specialised unit. The thermochemical calorie, 4.184 J, used on US food labels as 1 Calorie = 1 kilocalorie. Definition: NIST SP 811 Appendix B.8, factors for units listed alphabetically.

Formula version 0.1.0Reviewed