Calorie (cal)

The (thermochemical) calorie is exactly 4.184 J, roughly the heat needed to warm 1 g of water by 1 °C. The food "Calorie" is 1000 of these, a kilocalorie.

Symbol: cal

Quantity: energy, work and heat

SI relation: 1 cal = 4.184 J (exact)

Derivation: 1 cal (thermochemical) = 4.184 J (exact)

Exact: yes, by definition

Reference conditions. Thermochemical calorie, 4.184 J exactly. The International Table calorie is 4.1868 J.

Typical uses

Chemistry and calorimetry
Older physics literature
Not the food Calorie (kcal)

Convert calories to other units

1 cal in other energy units
Conversion	1 cal equals	Reverse
calorie to joule	4.184 J	joule to calorie
calorie to kilojoule	0.004184 kJ	kilojoule to calorie
calorie to kilocalorie	0.001 kcal	kilocalorie to calorie
calorie to kilowatt-hour	0.000001162222222 kWh	kilowatt-hour to calorie
calorie to BTU	0.003965666831 BTU	BTU to calorie
calorie to megajoule	0.000004184 MJ	megajoule to calorie
calorie to watt-hour	0.001162222222 Wh	watt-hour to calorie
calorie to therm	3.966613703 × 10⁻⁸ thm	therm to calorie
calorie to electronvolt	2.611447397 × 10¹⁹ eV	electronvolt to calorie
calorie to foot-pound	3.085960033 ft·lbf	foot-pound to calorie
calorie to erg	41840000 erg	erg to calorie

Open the Energy Converter to convert any value between all units.

Sources

Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "calorie (thermochemical) (cal_th)".

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.

Cite this page

APA

Scientific Converters. (2026, October 15). Calorie (cal). Retrieved October 17, 2026, from https://scientificconverters.com/units/calorie/

IEEE

Scientific Converters, "Calorie (cal)," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/units/calorie/