Kilocalories (kcal) to Joules (J) Converter
Enter a value to instantly convert between energy units.
1 Kilocalorie = 4184 Joule
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
J = kcal × 4184One kilocalorie (also called a dietary Calorie with capital C) equals exactly 4184 joules. Food labels worldwide use kilocalories because it's a practical size unit — a typical meal provides 500-1000 kcal, which is 2.1-4.2 megajoules in SI terms. Understanding this conversion is essential for comparing energy content across nutrition labels, planning dietary intake, and working in food science and nutrition research.
Source: NIST SP 811, Table B.8
Frequently Asked Questions
Real-World Examples
A nutrition scientist records 1 kcal from a single gram of carbohydrate = 4184 J for database.
1 kcal = 4184 J
Daily caloric requirement of 2000 kcal = 8.37 megajoules for research paper expressing energy in SI units.
2000 kcal = 8368000 J
A chocolate bar labeled 250 Calories (kcal) = 1.046 megajoules of energy stored in food.
250 kcal = 1046000 J
A typical meal of 500 kcal = 2.092 MJ, the approximate energy a sedentary person burns per meal.
500 kcal = 2092000 J