Convert calories to calories kcal
Convert calories to calories kcal instantly. 1 cal = 0.001 kcal. Formula, worked examples and a quick reference table.
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One calorie equals 0.001 kilocalories. To convert any number of calories to kilocalories, multiply by 0.001.
The converter above works in both directions and updates as you type. Below you will find the formula, a worked example and a reference table of common values.
Energy conversions sit between physics and the kitchen. The joule is the SI unit and the one every equation uses; the calorie survives on food labels, where it is actually a kilocalorie a thousand times larger than the physicist’s calorie; and the kilowatt-hour is what an electricity meter counts. All three measure the same quantity, which is why an appliance’s consumption and a meal’s energy content can, in principle, be compared directly.
calories to calories kcal formula
To go the other way, use calorie = kilocalorie ÷ 0.001.
About these units
The small calorie is the energy needed to warm one gram of water by one degree Celsius. It is a thousand times smaller than the "calorie" on a food label, which is really a kilocalorie.
The "calorie" on food labels is actually a kilocalorie — 1,000 small calories. One kilocalorie is 4.184 kilojoules.
Calorie is also written calories and cals. Kilocalorie is also written kilocalories, calories, food calories and Cal.
Sources
calories to calories kcal conversion table
| Calorie | Kilocalorie |
|---|---|
| 1 cal | 0.001 kcal |
| 2 cal | 0.002 kcal |
| 3 cal | 0.003 kcal |
| 5 cal | 0.005 kcal |
| 10 cal | 0.01 kcal |
| 20 cal | 0.02 kcal |
| 25 cal | 0.025 kcal |
| 50 cal | 0.05 kcal |
| 100 cal | 0.1 kcal |
| 250 cal | 0.25 kcal |
| 500 cal | 0.5 kcal |
| 1,000 cal | 1 kcal |
Frequently asked questions
How many kilocalories are in a calorie? +
There are 0.001 kilocalories in one calorie.
What is 10 cal in kcal? +
10 cal equals 0.01 kcal. Multiply 10 by 0.001.
How do I convert kilocalorie back to calorie? +
Use calorie = kilocalorie ÷ 0.001. The converter above handles both directions, or see our dedicated calories kcal to calories page.
How accurate is this calorie to kilocalorie conversion? +
The factor used is 0.001, carried at full double precision. Where a unit has an exact legal definition the factor is exact rather than approximate. Rounding is applied only to the displayed result, so the answer is never a calculation done on an already-rounded number.
Is there a quick way to estimate cal to kcal in my head? +
Divide by 1,000. That matches the true factor of 0.001 exactly, so no adjustment is needed for a mental estimate.