Joules (J) to Calories (cal) Converter
Enter a value to instantly convert between energy units.
1 Joule = 0.239 Calorie (thermochemical)
Key Formulas
Kilocalorie → Kilojoule
kJ = kcal × 4.184Kilojoule → Kilocalorie
kcal = kJ × 0.239006Kilowatt-Hour → Joule
J = kWh × 3600000Joule → Kilowatt-Hour
kWh = J × 2.77778e-7Formula
cal = J ÷ 4.184A thermochemical calorie (cal) is defined as exactly 4.184 joules — the energy to raise one gram of water by one degree Celsius. Calories are used in nutrition and food science, while joules are the SI standard. The calorie is a small unit: a single raisin provides about 10 calories.
Source: NIST SP 811, Table B.8
Frequently Asked Questions
Real-World Examples
A nutrition student calculating that a 4184 J energy bar contains exactly 1000 calories (1 kcal) for a presentation.
4184 J = 1000 cal
A chemist measuring 100 J of heat in a reaction records 23.9 cal for the lab report.
100 J = 23.9 cal
A food scientist analyzing a 2000 J serving size reports 478 calories for the nutrition label draft.
2000 J = 478 cal
A dietician calculating 50 J of energy from a sugar cube writes 11.95 cal for the patient handout.
50 J = 11.95 cal