kJ to Calories and Calories to kJ Converter

kilojoules to calories formula

kcal = kJ ÷ 4.184

1 kilojoule = 0.2390057361 calories, so multiply kilojoules by 0.2390057361. Going the other way, 1 calorie = 4.184000001 kilojoules.

kilojoules to calories table

How many calories in kilojoules?

100 kJ = 23.9006 kcal. There are 23.9006 calories in 100 kilojoules.

500 kJ = 119.503 kcal. There are 119.503 calories in 500 kilojoules.

1,000 kJ = 239.006 kcal. There are 239.006 calories in 1,000 kilojoules.

2,000 kJ = 478.011 kcal. There are 478.011 calories in 2,000 kilojoules.

8,700 kJ = 2,079.35 kcal. There are 2,079.35 calories in 8,700 kilojoules.

calories to kilojoules formula

kJ = kcal × 4.184

1 calorie = 4.184000001 kilojoules, so multiply calories by 4.184000001, or divide by 0.2390057361.

calories to kilojoules table

How many kilojoules in calories?

1 kcal = 4.184 kJ. There are 4.184 kilojoules in 1 calories.

100 kcal = 418.4 kJ. There are 418.4 kilojoules in 100 calories.

500 kcal = 2,092 kJ. There are 2,092 kilojoules in 500 calories.

1,000 kcal = 4,184 kJ. There are 4,184 kilojoules in 1,000 calories.

2,000 kcal = 8,368 kJ. There are 8,368 kilojoules in 2,000 calories.

How the KJ To Calories works

kJ to calories: which calorie

A calorie warms a gram of water by one degree and is 4.184 joules. The "calorie" on a label and in a diet is a thousand of those, a kilocalorie, written kcal or Cal. This page converts kJ to kcal, the food calorie. 1 kJ is 0.239 kcal, and the factor is exact because the thermochemical calorie is defined as 4.184 J.

Worked example: a 2,000 kJ ready meal

2,000 ÷ 4.184 = 478 kcal. Australian and New Zealand labels give kJ only; European labels give both; American labels give calories only. A 250 mL can of soft drink at 450 kJ is 108 kcal; a 50 g chocolate bar at 1,100 kJ is 263 kcal; a fast-food meal at 4,500 kJ is 1,075 kcal.

Worked example: the 8,700 kJ daily reference

8,700 ÷ 4.184 = 2,079 kcal. Australian labels give percentages of an 8,700 kJ daily intake, which is the 2,000 kcal reference used in Europe and the United States, rounded to a tidy kilojoule figure. A 10,000 kJ day is 2,390 kcal; 6,000 kJ is 1,434 kcal, a strict diet.

Exercise

Gym machines and fitness watches show calories, and the calorie they mean is the kilocalorie. A 30-minute run burning 1,300 kJ is 311 kcal. Body fat holds about 37,000 kJ per kilogram, 8,840 kcal — hence the old rule that a 500 kcal daily deficit, 2,100 kJ, loses about half a kilo a week.

Rule of thumb

Divide by 4 and take off 4%: 1,200 kJ is 300 − 12 = 288 kcal (exact: 287). Or just divide by four and remember the result is 4.6% high. The per-100 g figures on labels, converted, put most things in a familiar range: 1,500 kJ per 100 g is 360 kcal, biscuit territory.

Other units

A kilojoule is 1,000 joules, and a joule is a watt-second. 8,700 kJ a day is a continuous 100 W, which is why a resting human warms a room about as well as an old light bulb. A kilowatt-hour is 3,600 kJ, 860 kcal.

Worked example: a 2,000 calorie day

2,000 × 4.184 = 8,368 kJ. Australian labels round this to 8,700 kJ for the daily reference, and European labels print "8,400 kJ / 2,000 kcal". A 2,500 kcal day, the reference for men, is 10,460 kJ; a 1,500 kcal diet is 6,276 kJ. The tdee calculator gives your own figure.

Worked example: a 250 calorie chocolate bar

250 × 4.184 = 1,046 kJ. A can of cola at 139 kcal is 582 kJ; a Big Mac at 550 kcal is 2,301 kJ; a banana at 105 kcal is 439 kJ. Per 100 g, 500 kcal is 2,092 kJ, which is where chocolate, nuts and crisps sit.

Kilojoule to calories formula and table

The formula on this page is kcal = kJ ÷ 4.184, applied exactly before rounding for display.

How many calories in 100 kilojoules? 100 kJ is 23.9 kcal. Likewise 500 kJ is 119.5 kcal, 1,000 kJ is 239.01 kcal, 2,000 kJ is 478.01 kcal.

Kilojoule to calorie conversion table

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