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Calories to Kilocalories Converter

1 cal = 0.001 kcal (calorie → kilocalorie)

1 cal = 0.001 kcal

1 calorie equals 0.001 kilocalories. To convert calories to kilocalories, multiply the calorie value by 0.001. For quick reference: 1 cal = 0.001 kcal, 5 cal = 0.005 kcal, 10 cal = 0.01 kcal, 100 cal = 0.1 kcal.

When to use calories → kilocalories

Small calories to kilocalories divides by 1,000 — the kilocalorie is simply 1,000 thermochemical calories, each of 4.184 J. The arithmetic is trivial; the naming is the whole hazard. US food labels write 'Calories' (capital C) meaning kcal, physics texts write 'calories' meaning the small unit, and casual writing mixes both freely. A match burns about 1,000 small calories, which is just 1 kcal — a hundredth of a medium apple's 95 kcal. Always identify which calorie a source means before converting.

Thermochemistry textbooks sometimes report reaction energies in small calories per mole, a figure so large in raw calories that converting to kilocalories per mole is the only readable way to present it in a table. A reaction releasing 50,000 calories per mole is 50.00 kcal/mol, a typical bond-dissociation-energy scale. Because kilocalories per mole remains the standard unit in much of organic and biochemistry literature despite SI's preference for kJ/mol, this conversion bridges an older calorie-based dataset into the kcal/mol figures still printed in most chemistry reference tables.

How to convert calories to kilocalories

  1. Take your value

    Start with your value in calories.

  2. Multiply by 0.001

    Multiply the calorie value by 0.001. This is the exact conversion factor from calories to kilocalories.

  3. Read the result

    The product is your value in kilocalories. For example, 5 cal × 0.001 = 0.005 kcal.

Conversion formula

The exact factor from calories to kilocalories is 0.001.

Kilocalories = Calories × 0.001

Calories to Kilocalories conversion table

Fifty common reference values, hand-picked for skim utility. Use the calculator above for any value not listed.

Conversion table from calories to kilocalories
Calories (cal)Kilocalories (kcal)
0.001 cal1.0000 × 10^−6 kcal
0.01 cal1.0000 × 10^−5 kcal
0.1 cal0.0001 kcal
0.5 cal0.0005 kcal
1 cal0.001 kcal
1.5 cal0.0015 kcal
2 cal0.002 kcal
5 cal0.005 kcal
10 cal0.01 kcal
20 cal0.02 kcal
50 cal0.05 kcal
100 cal0.1 kcal
200 cal0.2 kcal
250 cal0.25 kcal
500 cal0.5 kcal
1000 cal1 kcal
2000 cal2 kcal
2500 cal2.5 kcal
3600 cal3.6 kcal
5000 cal5 kcal
7500 cal7.5 kcal
10000 cal10 kcal
25000 cal25 kcal
50000 cal50 kcal
100000 cal100 kcal
250000 cal250 kcal
500000 cal500 kcal
1000000 cal1000 kcal
2000000 cal2000 kcal
3600000 cal3600 kcal
5000000 cal5000 kcal
10000000 cal10000 kcal
25000000 cal25000 kcal
50000000 cal50000 kcal
100000000 cal100000 kcal
250000000 cal250000 kcal
500000000 cal500000 kcal
1000000000 cal1000000 kcal
2000000000 cal2000000 kcal
5000000000 cal5000000 kcal
10000000000 cal10000000 kcal
20000000000 cal20000000 kcal
50000000000 cal50000000 kcal
100000000000 cal100000000 kcal
1000000000000 cal1000000000 kcal
10000000000000 cal10000000000 kcal
100000000000000 cal100000000000 kcal
1000000000000000 cal1000000000000 kcal
10000000000000000 cal10000000000000 kcal
100000000000000000 cal100000000000000 kcal

Real-world reference

Burning a single dietary calorie of fat releases about 4.184 kJ of heat. A wooden match releases roughly 1,000 small calories.

Frequently asked questions

How many kilocalories are in 1 calorie?
1 calorie equals 0.001 kilocalories.
How do I convert calories to kilocalories?
Multiply the calorie value by 0.001. So x cal × 0.001 = the equivalent in kcal.
What is 5 calories in kilocalories?
5 calories equals 0.005 kilocalories.
What is 10 calories in kilocalories?
10 calories equals 0.01 kilocalories.
What is 100 calories in kilocalories?
100 calories equals 0.1 kilocalories.
How do I convert back from kilocalories to calories?
Multiply the kilocalorie value by 1000. For example, 1 kcal = 1000 cal.
Is the calorie bigger than the kilocalorie?
No. 1 calorie is smaller than 1 kilocalorie. It takes 1000 calories to equal 1 kilocalorie.
Are these conversion factors exact?
The factor is derived directly from the SI definitions of calorie and kilocalorie; the displayed value is rounded for readability, and the browser computes using IEEE 754 double-precision arithmetic.

About the calorie and the kilocalorie

The calorie

Convertitive uses the thermochemical (small) calorie, defined as exactly 4.184 joules — the energy needed to raise 1 g of water by 1 °C. Do not confuse it with the large calorie (kcal) used on US nutrition labels, which is 1,000 of these small calories.

The kilocalorie

The kilocalorie (kcal) equals exactly 4,184 joules — 1,000 small calories. This is the 'Calorie' (capital C) printed on US nutrition labels: when a food package says '250 Calories', it means 250 kcal. Outside the US, food energy is usually labeled in kJ as well.

Sources