UnitConvConvert
Energy

Convert calories to joules

1 cal=4.184J

Use the converter below to change any calories value into joules instantly — with formula, conversion table, and real-world examples.

4.184

Conversion formula

Forward
joules = calories × 4.184
Reverse
calories = joules × 0.239

Example: 10 cal × 4.184 = 41.84 J.

About both units

From

Calorie

cal

The gram calorie (small calorie) equals 4.184 joules — the energy to raise 1 g of water by 1 °C. It is a scientific unit, distinct from the nutrition "Calorie" (kcal). Largely replaced by joules in modern science.

Real-world: Raising 1 g of water 1 °C: 1 cal. A 100 kcal snack = 100,000 small calories.
Read full calorie reference →
To

Joule

J

The joule is the SI unit of energy, work and heat. Defined as one newton-metre or one watt-second. Named after James Prescott Joule who demonstrated the mechanical equivalent of heat. Lifting a 100 g apple 1 metre requires about 1 J.

Real-world: Lifting a 100 g apple 1 m: ≈ 1 J. 100 kcal snack: 418,400 J. Hand grenade: ~650 kJ.
Read full joule reference →

Calorie to Joule conversion table

Common calories to joules values for quick reference.

Calorie (cal)Joule (J)
1 cal4.184 J
10 cal41.84 J
100 cal418.4 J
500 cal2,092 J
1,000 cal4,184 J
5,000 cal20,920 J
10,000 cal41,840 J
50,000 cal209,200 J
100,000 cal418,400 J
500,000 cal2,092,000 J

Tips & common mistakes

Quick tips

  • 1 cal = 4.184 J. 1 kcal = 4184 J.
  • Scientific "calorie" and nutrition "Calorie" differ by 1000×.
  • Prefer joules in modern scientific writing.

Avoid these

  • Assuming "calories" on food labels means gram calories — they are kcal.
  • Mixing gram calories and kilocalories in calculations.
  • Confusing calorie (energy) with calorimeter (apparatus).

Frequently asked questions

How many joules in a calorie?
One calorie equals 4.184 joules.
How do I convert calories to joules?
Multiply the calorie value by 4.184 to get the equivalent in joules.
What is 100 calories in joules?
100 calories equals 418.4 joules.
Is a calorie bigger than a joule?
Yes. 1 calorie equals 4.184 joules, so one calorie is larger.
How to convert calories to joules without a calculator?
Multiply by 4.18 for a quick estimate; use a calculator for precise results.

Related energy conversions

📊 See full comparison matrix →

More from Calorie

cal → kJ
1 = 0.004184 kJ
cal → MJ
1 = 4.1840e-6 MJ
cal → kWh
1 = 1.1622e-6 kWh
cal → Wh
1 = 0.001162 Wh
cal → kcal
1 = 0.001 kcal
cal → BTU
1 = 0.003966 BTU
cal → eV
1 = 2.6114e19 eV
cal → thm
1 = 3.9657e-8 thm

More to Joule

kJ → J
1 = 1,000 J
MJ → J
1 = 1,000,000 J
kWh → J
1 = 3,600,000 J
Wh → J
1 = 3,600 J
kcal → J
1 = 4,184 J
BTU → J
1 = 1,055.06 J
eV → J
1 = 1.6022e-19 J
thm → J
1 = 105,505,585.3 J

Conversions in other categories

WeightKilogram → PoundLengthKilometer → MileTemperatureCelsius → FahrenheitVolumeLiter → US GallonAreaSquare Meter → Square FootSpeedKilometer per Hour → Mile per HourPressureBar → Pound per Square InchPowerKilowatt → Mechanical Horsepower