Skip to content
RK Calculator
Menu

Joules to Kilocalories Converter

Convert joules (watt-seconds) (J) to kilocalories (food Calories) (kcal), 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
0.000239005736138 kcal
kilojoules
0.001 kJ
megajoules
1 × 10⁻⁶ MJ
gigajoules
1 × 10⁻⁹ GJ
calories (thermochemical)
0.239005736138 cal
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 = 0.000239005736138 kcal

Show the working
  1. 1 J = 0.000239005736138 kcal
  2. 1 × 0.000239005736138 = 0.000239005736138 kcal

How to convert joules to kilocalories

1 kcal = 4,184 J, so divide by 4,184 to go from joules (watt-seconds) to kilocalories (food Calories) (1 J = 0.000239005736138 kcal).

kcal = J ÷ 4,184
J = kcal × 4,184

Worked example:

1 J = 0.000239005736138 kcal
5 × 0.000239005736138 = 0.00119502868069 kcal

Joules to kilocalories table

JoulesKilocalories
1 J0.000239005736138 kcal
2 J0.000478011472275 kcal
3 J0.000717017208413 kcal
4 J0.000956022944551 kcal
5 J0.00119502868069 kcal
6 J0.00143403441683 kcal
7 J0.00167304015296 kcal
8 J0.0019120458891 kcal
9 J0.00215105162524 kcal
10 J0.00239005736138 kcal
15 J0.00358508604207 kcal
20 J0.00478011472275 kcal
25 J0.00597514340344 kcal
30 J0.00717017208413 kcal
40 J0.00956022944551 kcal
50 J0.0119502868069 kcal
75 J0.0179254302103 kcal
100 J0.0239005736138 kcal
250 J0.0597514340344 kcal
500 J0.119502868069 kcal
1000 J0.239005736138 kcal

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).
Kilocalories (kcal)
Kilocalories (food Calories), a specialised unit. Definition: NIST SP 811 Appendix B.8, factors for units listed alphabetically.

Formula version 0.1.0Reviewed