Kilocalorie to Kilojoule Converter

Energy Converter

27 units available

Decimals:

From

To

4.184

1 kcal = 4.184 kJ

Formula:

kJ = kcal × 4.184

With your value: 1 kcal = 4.184 kJ

How big is that?

Everyday references on a logarithmic scale, all expressed in kilocalorie so you can sanity-check the result.

Heartbeat (1/4.2e+3 your value)0.000239 kcal

Your value1.00 kcal

AA battery charge (2.4× your value)2.39 kcal

Slice of bread (67× your value)66.9 kcal

Daily food intake (2.0e+3× your value)2.01e+3 kcal

Litre of petrol (8.2e+3× your value)8.17e+3 kcal

Other Kilocalorie to Kilojoule conversions

2 kcal to kJ 3 kcal to kJ 4 kcal to kJ 5 kcal to kJ 6 kcal to kJ 7 kcal to kJ 8 kcal to kJ

Kilocalorie to Kilojoule Conversion Table

Kilocalorie (kcal)	Kilojoule (kJ)
0.5	2.092
1	4.184
2	8.368
5	20.92
10	41.84
15	62.76
20	83.68
25	104.6
50	209.2
100	418.4
250	1,046
500	2,092
1000	4,184

Kilojoule to Kilocalorie Conversion Table

Kilojoule (kJ)	Kilocalorie (kcal)
0.5	0.119503
1	0.239006
2	0.478011
5	1.195029
10	2.390057
15	3.585086
20	4.780115
25	5.975143
50	11.950287
100	23.900574
250	59.751434
500	119.502868
1000	239.005736

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Kilocalorie (kcal)

Energy

Exact conversion

Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

Kilojoule (kJ)

Energy

Exact conversion

Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

How to Convert Kilocalorie to Kilojoule

To convert from Kilocalorie (kcal) to Kilojoule (kJ), multiply the value by 4.184.

Formula: kJ = kcal × 4.184

Reverse: kcal = kJ × 0.2390057361

Step-by-Step Example

Start with your value in Kilocalorie. For example: 5 kcal
Multiply by the conversion factor: 5 x 4.184
The result is: 20.92 kJ

About Kilocalorie

The kilocalorie (food Calorie) equals 1,000 calories or 4,184 joules. It is the standard unit for food energy content.

Common uses: nutrition, diet, food labeling.

About Kilojoule

The kilojoule (kJ) is a unit of energy and work. One kilojoule equals 1000 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: energy calculations, engineering and science, education.

Frequently Asked Questions

How many Kilojoule are in 1 Kilocalorie?

There are exactly 4.184 Kilojoule in 1 Kilocalorie. This means the conversion factor from Kilocalorie to Kilojoule is 4.184.

What is the formula to convert Kilocalorie to Kilojoule?

The formula to convert Kilocalorie to Kilojoule is: kJ = kcal × 4.184. For example, to convert 10 Kilocalorie to Kilojoule, you would multiply 10 by 4.184.

What is a Kilocalorie?