Convert Kilocalories (kcal) to Kilojoules (kJ)

1 kcal = 4.184 kJ

How many Kilojoules in a Kilocalorie?Printable chart →

Understanding the relationship between kilocalories and kilojoules is essential for effectively managing energy intake. The conversion factor between these two units is 1 kcal = 4.184 kJ, making it easy to switch between them for dietary or scientific purposes.

Kilocalorie (kcal)

Kilojoule (kJ)

4.184

≈ 4 3/16 kJ

Conversion Formula

kJ = kcal × 4.184

Reverse: kcal = kJ × 0.239006

Quick mental math: For a quick mental conversion, remember that 1 kcal is roughly 4 kJ.

Conversion Examples

1 kcal × 4.184 =

4.184 kJ

1 Kilocalories = 4.184 Kilojoules

5 kcal × 4.184 =

20.92 kJ

5 Kilocalories = 20.92 Kilojoules

10 kcal × 4.184 =

41.84 kJ

10 Kilocalories = 41.84 Kilojoules

25 kcal × 4.184 =

104.6 kJ

25 Kilocalories = 104.6 Kilojoules

50 kcal × 4.184 =

209.2 kJ

50 Kilocalories = 209.2 Kilojoules

100 kcal × 4.184 =

418.4 kJ

100 Kilocalories = 418.4 Kilojoules

Kilocalorie to Kilojoule Table

Quick convert your value:

kcal =—kJ

Start:Step:Rows:Precision:

Kilocalorie (kcal)	Kilojoule (kJ)	Fraction
1	4.184	4 3/16
2	8.368	8 3/8
3	12.552	12 35/64
4	16.736	16 47/64
5	20.92	20 59/64
6	25.104	25 7/64
7	29.288	29 9/32
8	33.472	33 15/32
9	37.656	37 21/32
10	41.84	41 27/32
11	46.024	46 1/32
12	50.208	50 13/64
13	54.392	54 25/64
14	58.576	58 37/64
15	62.76	62 49/64
16	66.944	66 15/16
17	71.128	71 1/8
18	75.312	75 5/16
19	79.496	79 1/2
20	83.68	83 11/16

Unit Definitions

What is a Kilocalorie (kcal)?

Metric (SI)Worldwide

A kilocalorie (kcal) is a unit of energy often used to quantify the amount of energy provided by food. It is equivalent to 1,000 calories in scientific terms.

History

The kilocalorie was originally defined as the amount of heat energy required to raise the temperature of one kilogram of water by one degree Celsius. It has been a standard measurement in nutrition since the late 19th century.

Current Use

Today, kilocalories are widely used in dietary guidelines and nutrition labels, helping consumers understand the energy content of food.

Learn more about Kilocalorie

What is a Kilojoule (kJ)?

Metric (SI)Worldwide

A kilojoule (kJ) is a unit of energy in the International System of Units (SI), where one kilojoule is equivalent to 1,000 joules.

History

The kilojoule was adopted as a standard unit of energy in the late 20th century as part of the SI system. It has roots in the work of physicists studying thermodynamics.

Current Use

Kilojoules are commonly used in scientific contexts and in many countries for food labeling, providing an alternative to kilocalories for measuring energy content.

Learn more about Kilojoule

Frequently Asked Questions

How many kilojoules are in 100 kcal?

To convert 100 kcal to kJ, you multiply by the conversion factor of 4.184. Thus, 100 kcal equals 418.4 kJ. This is particularly useful when planning meals, as many nutrition labels list energy content in kilojoules.

What is the energy content of a food item labeled as 250 kcal?

Using the conversion factor, 250 kcal can be converted to kilojoules by multiplying by 4.184. Therefore, 250 kcal equals 1046 kJ. This knowledge helps when comparing food items that might have different labeling standards.

If I consume 1500 kJ, how many kilocalories is that?

To convert kilojoules back to kilocalories, you use the reverse factor of 0.239006. Thus, 1500 kJ equals approximately 358.51 kcal. This is crucial for anyone tracking their daily caloric intake for weight management.

How can I relate exercise energy expenditure in kcal to kJ?

If a workout burns 500 kcal, converting this to kilojoules involves multiplying by 4.184, resulting in 2092 kJ. Understanding this conversion can help in effectively planning post-exercise nutrition for recovery.

What is the energy content of a snack with 200 kcal in kilojoules?

To find out how many kilojoules are in 200 kcal, multiply by the conversion factor 4.184. This gives you 836.8 kJ. Knowing this can assist in maintaining a balanced energy intake throughout the day.

Popular Energy Conversions

Kilowatt to HorsepowerkW → HP Calorie to Kilocaloriecal → kcal Joule to CalorieJ → cal Kilowatt-hour to BTUkWh → BTU BTU to JouleBTU → J Kilocalorie to Joulekcal → J

Convert Kilocalorie to Other Units

Kilocalorie to Joule→ J Kilocalorie to Kilojoule→ kJ Kilocalorie to Calorie→ cal Kilocalorie to Watt-hour→ Wh Kilocalorie to Kilowatt-hour→ kWh Kilocalorie to BTU→ BTU Kilocalorie to Kilowatt→ kW Kilocalorie to Horsepower→ HP

Related Conversions

Joule to KilojouleJ → kJ Joule to KilocalorieJ → kcal Kilojoule to JoulekJ → J Kilojoule to CaloriekJ → cal Kilojoule to KilocaloriekJ → kcal