Kilojoules to Calories

Convert kilojoules to calories instantly, with a full reference table.

Kilojoules to Kilocalories conversion table
Kilojoules (kJ)Kilocalories (kcal)
10023.9
20047.8
30071.7
40095.6
500119.5
600143.4
700167.3
800191.2
900215.1
1,000239
Formula: One kilojoule equals 0.239006 kilocalories (Calories). To convert kilojoules to Calories, multiply by 0.239006. For example, 1000 kJ equals 239.0 kcal.

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About the Kilojoules to Calories

This Kilojoules to Calories converter turns a kilojoule (kJ) energy figure into Calories, the unit most people mean when they count calories on a food label. The maths is fixed: one Calorie (kcal) equals exactly 4.184 kilojoules, so to go from kJ to Calories you divide by 4.184, or equivalently multiply by 0.239006. Enter the kilojoule value printed on your packet and the tool returns the matching Calorie figure instantly, so you can compare a product labelled in kJ against a recipe, app, or target that is written in Calories.

The conversion is most useful when your food information and your goal speak different units. Packaged food sold in Australia and New Zealand must, by law, show energy in kilojoules under Food Standards Australia New Zealand rules, while diet apps, US labels, and most online recipes report Calories. A protein bar marked 850 kJ, for example, is about 203 Calories. Use the converter to log Australian groceries in a Calorie-based tracker, to read an imported label, to check a gym machine that reports kJ burned, or to follow a kJ-based daily energy target in familiar Calorie terms.

Behind the scenes the tool applies the internationally agreed thermochemical factor of 4.184 kJ per Calorie, the value recommended by the IUNS for food energy. Note one terminology trap: the everyday "Calorie" on a food label is actually a kilocalorie (1,000 small calories), and this converter outputs that food Calorie (kcal), not the tiny gram-calorie used in physics. Some sources round the factor to 4.2 or even 4 for mental arithmetic; this tool keeps the full 4.184 so your numbers stay accurate. Halving the kJ figure and shaving a little off is a decent rough check.

Everything runs locally in your browser. The kilojoule value you type is never uploaded, stored, or shared, so you can convert nutrition figures or personal energy targets privately. Results are mathematically exact to the conversion factor, but remember that the energy printed on any label is itself an estimate, typically rounded and based on average composition, so treat a converted Calorie figure as a close guide rather than a measurement to the last digit.

Frequently asked questions

How do I convert kilojoules to calories?

Divide the kilojoule value by 4.184, or multiply it by 0.239006. For example, 1,000 kJ divided by 4.184 is about 239 Calories.

How many calories are in 1 kilojoule?

One kilojoule equals roughly 0.239 Calories (kcal). Put the other way around, one Calorie equals 4.184 kilojoules.

Why do Australian food labels use kilojoules instead of calories?

The kilojoule is the SI metric unit of energy, and Australia adopted the metric system in the 1970s. Food Standards Australia New Zealand requires packaged food to show energy in kilojoules, so this tool helps you read those labels in Calories.

Is a Calorie the same as a kilocalorie (kcal)?

Yes. The "Calorie" with a capital C on a food label is a kilocalorie, equal to 1,000 small calories. This converter returns that food Calorie, which is what diet apps and US labels mean by calories.

Should I divide kilojoules by 4.2 or 4.184?

Use 4.184 for accuracy, which is the official thermochemical factor for food energy. Dividing by 4.2, or even by 4, gives a quick rough estimate but will be slightly off.

From our blog

Centimeters to Feet: The Quick Method, the Inch Trap, and a Cheat Sheet

By the Super Simple Digital Tools Team · Updated June 2026

Most centimeter-to-feet conversions exist for one reason: someone wrote a measurement in metric and someone else needs it in imperial. Heights on medical records, product dimensions on international listings, and measurements in foreign instructions all arrive in centimeters, while feet and inches remain the everyday language for height and room sizes across the United States and United Kingdom. The good news is that the conversion is built on a single exact number, so once you know it, you never have to guess.

That number is 30.48: one foot is defined as exactly 30.48 centimeters. To get decimal feet, divide your centimeter figure by 30.48. So 200 cm divided by 30.48 is about 6.56 feet. Decimal feet are mathematically correct but awkward to picture, which is why the second step matters. Take the part after the decimal point, multiply it by 12, and you have the inches. For 200 cm, the 0.56 becomes about 6.7 inches, giving roughly 6 feet 7 inches, the kind of figure you would actually say out loud.

The single biggest error people make is confusing decimal feet with feet and inches. A height of 5 feet 11 inches is not 5.11 feet. The .11 in 5.11 feet is eleven hundredths of a foot, which is only about 1.3 inches, so 5.11 feet is about 156 cm. Genuine 5 feet 11 inches is about 180 cm, a difference of nearly two and a half centimeters. Whenever a form has a single decimal feet box, do the inch math separately, or use a converter that gives you feet and inches directly.

A few anchor values make mental estimates easy. 152.4 cm is exactly 5 feet. 160 cm is about 5 feet 3 inches, 165 cm is about 5 feet 5 inches, 170 cm is about 5 feet 7 inches, 175 cm is about 5 feet 9 inches, and 180 cm is about 5 feet 11 inches. Notice that each additional 2.5 cm adds roughly an inch. Memorizing just the 5-foot and 6-foot marks lets you sanity-check almost any height conversion in your head before trusting a screen.

If you need precision rather than a rough idea, hold on to the unrounded result. Because the conversion factor is exact, the only error in a digital tool comes from how many decimal places it displays. For documents like engineering drawings, shipping specs, or official forms, copy the full-precision value and round only at the very end. For casual use, feet and inches rounded to the nearest inch is almost always what people expect to see.

  • Divide by 30.48 for decimal feet, then multiply only the leftover decimal by 12 to get inches.
  • Never type a height like 5'11" as 5.11 in a decimal feet box; that equals about 156 cm, not 180 cm.
  • Memorize 152.4 cm = 5 feet exactly and add roughly one inch per 2.5 cm to estimate any height fast.
  • For official paperwork, keep the unrounded figure and round only at the final step to avoid stacking errors.

Read the full guide →

Tool by the Super Simple Digital Tools Team. Reviewed by our editorial team. Free to use, no signup required.

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