Kcal to kJ Converter

Convert kilocalories to kilojoules: 1 kcal = 4.184 kJ. Exact factor, formula and a conversion chart.

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Result

1 kcal =4.184 kJ
1 kcal
4.184 kJ
1 kJ
0.239006 kcal
How it's calculated

kilojoules = kilocalories × 4.184

To convert kcal to kJ, multiply by 4.184.

kcal in every unit

joule4,184 J
kilojoule4.184 kJ
calorie1,000 cal
watt-hour1.16222 Wh
kilowatt-hour0.00116222 kWh
British thermal unit3.96567 BTU

kcal to kJ conversion chart

kilocalorie (food calorie) (kcal)kilojoule (kJ)
1 kcal4.184 kJ
2 kcal8.368 kJ
3 kcal12.552 kJ
4 kcal16.736 kJ
5 kcal20.92 kJ
6 kcal25.104 kJ
7 kcal29.288 kJ
8 kcal33.472 kJ
9 kcal37.656 kJ
10 kcal41.84 kJ
12 kcal50.208 kJ
15 kcal62.76 kJ
20 kcal83.68 kJ
25 kcal104.6 kJ
50 kcal209.2 kJ
100 kcal418.4 kJ

How many kilojoules are in 1 kilocalorie (food calorie)?

1 kilocalorie (food calorie) = 4.184 kilojoules. To convert kilocalories to kilojoules, multiply by 4.184. For example, 10 kcal = 41.84 kJ and 100 kcal = 418.4 kJ. Enter any value above for an exact result.

The Unit Converter changes a value from one unit to another across 11 kinds of measurement: length, weight, temperature, volume, area, speed, time, digital storage, energy, pressure and fuel economy. It covers metric units (centimetres, kilograms, litres), US and UK imperial units (inches, pounds, gallons) and everyday ones such as cups, stones, acres and kilowatt-hours.

Conversions use the official definitions — 1 inch is exactly 2.54 cm, 1 pound exactly 0.45359237 kg, 1 US gallon exactly 3.785411784 litres — and the page shows the factor, the formula, the value in every other unit and a chart of common values, so you can check or reuse the numbers.

When to use it

  • Converting height and weight between metric and imperial (cm ↔ feet and inches, kg ↔ lbs).
  • Cooking with recipes from another country (cups, tablespoons, ml, grams, ounces).
  • Reading weather and oven temperatures in Celsius or Fahrenheit.
  • Property sizes in square feet, square metres, acres and hectares.
  • File sizes (MB ↔ GB), fuel economy (mpg ↔ L/100 km) and tyre pressure (psi ↔ bar).

Tips for better results

  • US and UK gallons and pints differ by about 20% — check which one a recipe or car manual uses.
  • Temperature is not a simple multiplication: use the formula shown (°F = °C × 9/5 + 32).
  • Storage makers use 1 GB = 1,000 MB, while some operating systems show GiB (1,024 MiB) — both are listed.

How to use the Unit Converter

  1. Choose the measurement, such as length or temperature.
  2. Enter the value and pick the units to convert from and to.
  3. Read the result, the value in every other unit and the conversion chart below.

Frequently asked questions

How do I convert kilocalories to kilojoules?

To convert kilocalories to kilojoules, multiply by 4.184. For example, 10 kcal = 41.84 kJ.

How do I convert kilojoules back to kilocalories?

Press the swap button between the units. 1 kJ = 0.239006 kcal.

Is the conversion exact?

Yes. It uses the official definitions of the units; results are only rounded to six significant digits for display.

Are the conversions exact?

Yes. Units are converted with their defined factors — for example 1 inch is exactly 2.54 cm and 1 pound is exactly 0.45359237 kg — and results are rounded to six significant digits only for display.

Are cups and gallons US or UK?

Cups, pints, quarts and gallons are US customary units unless marked UK. UK (imperial) gallons and pints are listed separately because they are about 20% larger.

How many centimetres are in an inch?

Exactly 2.54 cm. To convert inches to centimetres, multiply by 2.54; to convert centimetres to inches, divide by 2.54.

How do I convert kilograms to pounds?

Multiply by 2.20462 (1 kg = 2.20462 lb). To convert pounds to kilograms, multiply by 0.453592.