Energy Converter

Convert between different units of energy

1 Kilocalorie (kcal)=0 Kilojoule (kJ)

Conversion Formula

Kilojoule = Kilocalorie × 4.184

Step-by-Step Calculation:

To convert 1 Kilocalorie to Kilojoule, multiply by 4.184 to get 4.184 Kilojoule.

Unit Proportion Ratio1 Kilocalorie = 4.184 Kilojoule

Conversion Table

Kilocalorie (kcal)Kilojoule (kJ)
0.010.0418
0.10.4184
14.184
28.368
520.92
1041.84
2083.68
50209.2
100418.4

Unit Information & History

Joule

Definition: The SI unit of energy, defined as the energy transferred to an object when a force of one newton acts on it over a distance of one meter.

History: Named after James Prescott Joule, who demonstrated the relationship between mechanical work and heat in the 19th century.

Current Use: The standard scientific unit for all forms of energy (mechanical, thermal, electrical). Food energy is also measured in kilojoules in many countries.

Calorie

Definition: Originally defined as the amount of heat energy needed to raise the temperature of one gram of water by one degree Celsius.

History: First defined by Nicolas Clément in 1824. Confusingly, the "Calorie" on food labels is actually a kilocalorie (1,000 small calories).

Current Use: Widely used in chemistry (small calories) and almost exclusively used for food energy (kilocalories) in the US.

Kilowatt-hour

Definition: A unit of energy equal to one kilowatt of power sustained for one hour.

History: Developed with the rise of the electrical utility industry to measure electricity consumption over time.

Current Use: The standard unit for electricity billing worldwide.

Frequently Asked Questions

Quick answers to common questions

Q:How many joules in a calorie?

One thermochemical calorie equals 4.184 joules. To convert calories to joules, multiply by 4.184.

Q:How many kilowatt-hours in a joule?

One kilowatt-hour equals 3.6 million joules. To convert joules to kWh, divide by 3,600,000.

Q:What is the difference between watts and joules?

A watt is a rate of energy use (joules per second), while a joule is a unit of energy itself. Calories in food are actually kilocalories.