Skip to content
RK Calculator
Menu

Calories to Kilojoules Converter

Convert calories (thermochemical) (cal) to kilojoules (kJ), 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.

About valueA number, fraction (3/8), mixed number (1 1/2), scientific notation (2.5e6) or a simple sum such as 2*3.
About toThe unit you want the answer in. Swap exchanges the two units.
Result
Result
0.004184 kJ
joules (watt-seconds)
4.184 J
megajoules
4.184 × 10⁻⁶ MJ
gigajoules
4.184 × 10⁻⁹ GJ
kilocalories (food Calories)
0.001 kcal
megacalories
1 × 10⁻⁶ Mcal
watt-hours
0.00116222222222 Wh
kilowatt-hours
1.16222222222 × 10⁻⁶ kWh
megawatt-hours
1.16222222222 × 10⁻⁹ MWh
British thermal units (IT)
0.00396566683139 Btu
million Btu
3.96566683139 × 10⁻⁹ MMBtu
therms (100,000 Btu)
3.96566683139 × 10⁻⁸ thm
quads (10¹⁵ Btu)
3.96566683139 × 10⁻¹⁸ quad
electronvolts
2.61144739675 × 10¹⁹ eV
kiloelectronvolts
2.61144739675 × 10¹⁶ keV
megaelectronvolts
26,114,473,967,500 MeV

1 cal = 0.004184 kJ

Show the working
  1. 1 cal = 0.004184 kJ
  2. 1 × 0.004184 = 0.004184 kJ

How to convert calories to kilojoules

1 cal = 0.004184 kJ, so multiply by 0.004184 to go from calories (thermochemical) to kilojoules. Going the other way, 1 kJ = 239.005736138 cal.

kJ = cal × 0.004184
cal = kJ × 239.005736138

Worked example:

1 cal = 0.004184 kJ
5 × 0.004184 = 0.02092 kJ

Calories to kilojoules table

CaloriesKilojoules
1 cal0.004184 kJ
2 cal0.008368 kJ
3 cal0.012552 kJ
4 cal0.016736 kJ
5 cal0.02092 kJ
6 cal0.025104 kJ
7 cal0.029288 kJ
8 cal0.033472 kJ
9 cal0.037656 kJ
10 cal0.04184 kJ
15 cal0.06276 kJ
20 cal0.08368 kJ
25 cal0.1046 kJ
30 cal0.12552 kJ
40 cal0.16736 kJ
50 cal0.2092 kJ
75 cal0.3138 kJ
100 cal0.4184 kJ
250 cal1.046 kJ
500 cal2.092 kJ
1000 cal4.184 kJ

About the units

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