Convert Calorie to Kilocalorie
1 calorie = 0.001 kilocalorie (kcal). For example, 10 calorie = 0.01 kilocalorie and 100 calorie = 0.1 kilocalorie. Type any value below to convert calorie to kilocalorie both ways — it runs entirely in your browser.
Quick answer: Calorie to Kilocalorie
1 Calorie = 0.001 Kilocalorie (cal → kcal). To convert calorie to kilocalorie, multiply by 0.001. To convert kilocalorie to calorie, multiply by 1,000. The converter at the top does this instantly and both ways; the sections below give the formula, worked examples, a full conversion chart and answers to the most common calorie-to-kilocalorie questions.
How to convert Calorie to Kilocalorie
To convert calorie to kilocalorie, multiply the number of calorie by the conversion factor 0.001, because 1 cal = 0.001 kcal. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 kcal = 1,000 cal, so you divide by 0.001 (or multiply by 1,000) to turn kilocalorie back into calorie.
kcal = cal × 0.001 ·
cal = kcal × 1,000
- Write down the value you want to convert, in calorie.
- Multiply it by 0.001.
- The result is the same area/length/quantity expressed in kilocalorie.
Calorie to Kilocalorie — worked examples
Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 calorie is 0.005 kilocalorie because 5 cal × 0.001 = 0.005 kcal.
| Calorie | Calculation | Kilocalorie |
|---|---|---|
| 1 cal | 1 cal × 0.001 = 0.001 kcal | 0.001 kcal |
| 2 cal | 2 cal × 0.001 = 0.002 kcal | 0.002 kcal |
| 3 cal | 3 cal × 0.001 = 0.003 kcal | 0.003 kcal |
| 5 cal | 5 cal × 0.001 = 0.005 kcal | 0.005 kcal |
| 7 cal | 7 cal × 0.001 = 0.007 kcal | 0.007 kcal |
| 10 cal | 10 cal × 0.001 = 0.01 kcal | 0.01 kcal |
| 12 cal | 12 cal × 0.001 = 0.012 kcal | 0.012 kcal |
| 15 cal | 15 cal × 0.001 = 0.015 kcal | 0.015 kcal |
| 20 cal | 20 cal × 0.001 = 0.02 kcal | 0.02 kcal |
| 25 cal | 25 cal × 0.001 = 0.025 kcal | 0.025 kcal |
| 50 cal | 50 cal × 0.001 = 0.05 kcal | 0.05 kcal |
| 100 cal | 100 cal × 0.001 = 0.1 kcal | 0.1 kcal |
Common Calorie to Kilocalorie conversions
These are the calorie-to-kilocalorie values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:
- 1 calorie = 0.001 kilocalorie
- 2 calorie = 0.002 kilocalorie
- 2.5 calorie = 0.0025 kilocalorie
- 3 calorie = 0.003 kilocalorie
- 4 calorie = 0.004 kilocalorie
- 5 calorie = 0.005 kilocalorie
- 6 calorie = 0.006 kilocalorie
- 7 calorie = 0.007 kilocalorie
- 8 calorie = 0.008 kilocalorie
- 9 calorie = 0.009 kilocalorie
- 10 calorie = 0.01 kilocalorie
- 12 calorie = 0.012 kilocalorie
- 15 calorie = 0.015 kilocalorie
- 20 calorie = 0.02 kilocalorie
- 25 calorie = 0.025 kilocalorie
- 30 calorie = 0.03 kilocalorie
- 50 calorie = 0.05 kilocalorie
- 75 calorie = 0.075 kilocalorie
- 100 calorie = 0.1 kilocalorie
- 200 calorie = 0.2 kilocalorie
- 500 calorie = 0.5 kilocalorie
- 1000 calorie = 1 kilocalorie
Calorie to Kilocalorie conversion chart (both directions)
The chart below converts calorie to kilocalorie and kilocalorie to calorie side by side, so it works whichever way you need. 1 calorie = 0.001 kilocalorie, and 1 kilocalorie = 1,000 calorie.
| Calorie → Kilocalorie | Kilocalorie → Calorie |
|---|---|
| 0.25 cal = 0.00025 kcal | 0.25 kcal = 250 cal |
| 0.5 cal = 0.0005 kcal | 0.5 kcal = 500 cal |
| 1 cal = 0.001 kcal | 1 kcal = 1,000 cal |
| 2 cal = 0.002 kcal | 2 kcal = 2,000 cal |
| 3 cal = 0.003 kcal | 3 kcal = 3,000 cal |
| 4 cal = 0.004 kcal | 4 kcal = 4,000 cal |
| 5 cal = 0.005 kcal | 5 kcal = 5,000 cal |
| 6 cal = 0.006 kcal | 6 kcal = 6,000 cal |
| 7 cal = 0.007 kcal | 7 kcal = 7,000 cal |
| 8 cal = 0.008 kcal | 8 kcal = 8,000 cal |
| 9 cal = 0.009 kcal | 9 kcal = 9,000 cal |
| 10 cal = 0.01 kcal | 10 kcal = 10,000 cal |
| 12 cal = 0.012 kcal | 12 kcal = 12,000 cal |
| 15 cal = 0.015 kcal | 15 kcal = 15,000 cal |
| 20 cal = 0.02 kcal | 20 kcal = 20,000 cal |
| 25 cal = 0.025 kcal | 25 kcal = 25,000 cal |
| 30 cal = 0.03 kcal | 30 kcal = 30,000 cal |
| 40 cal = 0.04 kcal | 40 kcal = 40,000 cal |
| 50 cal = 0.05 kcal | 50 kcal = 50,000 cal |
| 75 cal = 0.075 kcal | 75 kcal = 75,000 cal |
| 100 cal = 0.1 kcal | 100 kcal = 100,000 cal |
| 150 cal = 0.15 kcal | 150 kcal = 150,000 cal |
| 200 cal = 0.2 kcal | 200 kcal = 200,000 cal |
| 250 cal = 0.25 kcal | 250 kcal = 250,000 cal |
| 500 cal = 0.5 kcal | 500 kcal = 500,000 cal |
| 1000 cal = 1 kcal | 1000 kcal = 1,000,000 cal |
Calorie vs Kilocalorie: which is bigger?
A kilocalorie is the larger unit: one kilocalorie equals 1,000 calories. Put another way, you need 1,000 calories to make a single kilocalorie.
What is a Calorie? History, origin and usage
The calorie — from the Latin calor, “heat” — was introduced as a heat unit by Nicolas Clément in lectures around 1819-1824. The small (gram) calorie is roughly the heat needed to warm one gram of water by one degree Celsius; the modern thermochemical calorie is fixed at exactly 4.184 joules.
In chemistry and physics “cal” usually means the small calorie, used for reaction heats and specific-heat work, though the joule has officially replaced it within SI since 1948. In nutrition the capital-C “Calorie” actually means a kilocalorie — a thousand of these small calories.
The confusing food “Calorie” is really a kilocalorie: the nutritionist Wilbur Atwater popularised the capital-C convention in 1887, following Marcellin Berthelot’s 1879 distinction. So a 200-“Calorie” snack actually holds 200,000 of the physicists’ small calories.
What is a Kilocalorie? History, origin and usage
The kilocalorie is 1,000 small calories, and it is the unit behind the familiar food “Calorie” (often written with a capital C). It descends from the calorimetry of Nicolas Clément and the 19th-century nutrition science of Marcellin Berthelot and Wilbur Atwater, who needed a human-scale unit for the energy in food.
The kilocalorie is the energy figure on nutrition labels in the United States and many other countries, where it is simply called the “calorie.” Dietitians, food scientists and fitness apps use kcal to track energy intake and expenditure.
When a label says a food has “250 calories,” it means 250 kilocalories — 250,000 of the physicists’ small calories. The macronutrients differ in energy density: fat supplies about 9 kcal per gram, while carbohydrate and protein each supply about 4 kcal per gram.
Convert 1 Calorie to other units
It can help to see a calorie next to the other units it is commonly compared with. One calorie (cal) is equal to:
| 1 Calorie equals | Unit |
|---|---|
| 4.184 J | Joule |
| 4.184 N·m | Newton-metre |
| 0.004184 kJ | Kilojoule |
| 0.000004184 MJ | Megajoule |
| 0.001162222 Wh | Watt-hour |
| 0.000001162222 kWh | Kilowatt-hour |
| 0.000000001162222 MWh | Megawatt-hour |
| 3.08596 ft·lbf | Foot-pound |
| 26,114,470,000,000 MeV | Megaelectronvolt |
| 0.001 kcal | Kilocalorie |
| 0.003965667 BTU | British Thermal Unit |
Convert 1 Kilocalorie to other units
One kilocalorie (kcal) is equal to:
| 1 Kilocalorie equals | Unit |
|---|---|
| 4,184 J | Joule |
| 4,184 N·m | Newton-metre |
| 4.184 kJ | Kilojoule |
| 0.004184 MJ | Megajoule |
| 1.162222 Wh | Watt-hour |
| 0.001162222 kWh | Kilowatt-hour |
| 0.000001162222 MWh | Megawatt-hour |
| 3,085.96 ft·lbf | Foot-pound |
| 26,114,470,000,000,000 MeV | Megaelectronvolt |
| 1,000 cal | Calorie |
| 3.965667 BTU | British Thermal Unit |
Tips for converting Calorie to Kilocalorie
- To go from calorie to kilocalorie, multiply by 0.001; to go back, divide by 0.001 (or multiply by 1,000).
- For a quick mental estimate, remember that 1 calorie ≈ 0.001 kilocalorie, so 10 calorie ≈ 0.01 kilocalorie.
- The converter above keeps full precision; the tables round for readability, so use the tool for exact figures.
- Both fields update live as you type — change either side to convert in that direction.
How to use this Calorie to Kilocalorie converter
Type a number into the Calorie field and the equivalent in Kilocalorie appears instantly — there is no “convert” button to press and nothing is sent to a server, so it works offline once the page has loaded and is safe for any data. You can also type into the Kilocalorie field to convert the other way (kilocalorie to calorie). Use the swap control to flip the two units, and copy the result with a single click. Because the calculation runs in your browser with full floating-point precision, the converter is more exact than the rounded figures shown in the reference chart above — use the chart for quick look-ups and the tool for precise work.
Accuracy and method
Every figure on this page — the formula, the worked examples, the conversion chart and the “convert to other units” tables — is computed from a single verified conversion factor (1 cal = 0.001 kcal), never copied from a hand-typed lookup table that could drift. That factor is derived from each unit’s definition in terms of a common base unit, and an automated check re-verifies all of the site’s factors on every update, so the numbers here stay correct over time. This matters for calorie-to-kilocalorie conversions because a small rounding error in a published table compounds quickly at larger quantities; computing from the exact factor avoids that.
Sources
- BIPM — The International System of Units (SI Brochure) — the defining document for the SI, published by the International Bureau of Weights and Measures. It fixes the base unit that this conversion resolves to, which is why the factor here can be exact rather than approximate.
- NIST — Definitions of the SI base units — the US National Institute of Standards and Technology reference for the SI base units, used here as an independent cross-check on the base-unit definition.
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Frequently asked questions
- How many kilocalorie are in 1 calorie?
- 1 calorie = 0.001 kilocalorie (kcal). To convert any number of calorie to kilocalorie, multiply by 0.001.
- How do I convert calorie to kilocalorie?
- Multiply the number of calorie by 0.001. For example, 10 calorie = 10 × 0.001 = 0.01 kilocalorie, and 25 calorie = 0.025 kilocalorie.
- How many calorie are in 1 kilocalorie?
- 1 kilocalorie = 1,000 calorie. So to convert kilocalorie back to calorie, multiply by 1,000.
- What is the formula to convert calorie to kilocalorie?
- kilocalorie = calorie × 0.001. The reverse formula is calorie = kilocalorie × 1,000.
- How much is 100 calorie in kilocalorie?
- 100 calorie = 0.1 kilocalorie. (And 1000 calorie = 1 kilocalorie.)
- Which is bigger, a calorie or a kilocalorie?
- A kilocalorie is larger: 1 kilocalorie = 1,000 calorie.
- Is this calorie to kilocalorie converter accurate?
- Yes — every value is computed from the exact 0.001 kcal per cal factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
- Can I convert kilocalorie to calorie too?
- Yes. The converter works both ways — enter a value in either field. 1 kilocalorie = 1,000 calorie.