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Calories to Joules Converter

Convert calories (thermochemical) (cal) 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.

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
4.184 J
kilojoules
0.004184 kJ
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 = 4.184 J

Show the working
  1. 1 cal = 4.184 J
  2. 1 × 4.184 = 4.184 J

How to convert calories to joules

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

J = cal × 4.184
cal = J × 0.239005736138

Worked example:

1 cal = 4.184 J
5 × 4.184 = 20.92 J

Calories to joules table

CaloriesJoules
1 cal4.184 J
2 cal8.368 J
3 cal12.552 J
4 cal16.736 J
5 cal20.92 J
6 cal25.104 J
7 cal29.288 J
8 cal33.472 J
9 cal37.656 J
10 cal41.84 J
15 cal62.76 J
20 cal83.68 J
25 cal104.6 J
30 cal125.52 J
40 cal167.36 J
50 cal209.2 J
75 cal313.8 J
100 cal418.4 J
250 cal1,046 J
500 cal2,092 J
1000 cal4,184 J

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.
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