Convert Calorie to Joule
1 calorie = 4.184 joule (J). For example, 10 calorie = 41.84 joule and 100 calorie = 418.4 joule. Type any value below to convert calorie to joule both ways — it runs entirely in your browser.
Quick answer: Calorie to Joule
1 Calorie = 4.184 Joule (cal → J). To convert calorie to joule, multiply by 4.184. To convert joule to calorie, multiply by 0.2390057. 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-joule questions.
How to convert Calorie to Joule
To convert calorie to joule, multiply the number of calorie by the conversion factor 4.184, because 1 cal = 4.184 J. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 J = 0.2390057 cal, so you divide by 4.184 (or multiply by 0.2390057) to turn joule back into calorie.
J = cal × 4.184 ·
cal = J × 0.2390057
- Write down the value you want to convert, in calorie.
- Multiply it by 4.184.
- The result is the same area/length/quantity expressed in joule.
Calorie to Joule — worked examples
Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 calorie is 20.92 joule because 5 cal × 4.184 = 20.92 J.
| Calorie | Calculation | Joule |
|---|---|---|
| 1 cal | 1 cal × 4.184 = 4.184 J | 4.184 J |
| 2 cal | 2 cal × 4.184 = 8.368 J | 8.368 J |
| 3 cal | 3 cal × 4.184 = 12.552 J | 12.552 J |
| 5 cal | 5 cal × 4.184 = 20.92 J | 20.92 J |
| 7 cal | 7 cal × 4.184 = 29.288 J | 29.288 J |
| 10 cal | 10 cal × 4.184 = 41.84 J | 41.84 J |
| 12 cal | 12 cal × 4.184 = 50.208 J | 50.208 J |
| 15 cal | 15 cal × 4.184 = 62.76 J | 62.76 J |
| 20 cal | 20 cal × 4.184 = 83.68 J | 83.68 J |
| 25 cal | 25 cal × 4.184 = 104.6 J | 104.6 J |
| 50 cal | 50 cal × 4.184 = 209.2 J | 209.2 J |
| 100 cal | 100 cal × 4.184 = 418.4 J | 418.4 J |
Common Calorie to Joule conversions
These are the calorie-to-joule 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 = 4.184 joule
- 2 calorie = 8.368 joule
- 2.5 calorie = 10.46 joule
- 3 calorie = 12.552 joule
- 4 calorie = 16.736 joule
- 5 calorie = 20.92 joule
- 6 calorie = 25.104 joule
- 7 calorie = 29.288 joule
- 8 calorie = 33.472 joule
- 9 calorie = 37.656 joule
- 10 calorie = 41.84 joule
- 12 calorie = 50.208 joule
- 15 calorie = 62.76 joule
- 20 calorie = 83.68 joule
- 25 calorie = 104.6 joule
- 30 calorie = 125.52 joule
- 50 calorie = 209.2 joule
- 75 calorie = 313.8 joule
- 100 calorie = 418.4 joule
- 200 calorie = 836.8 joule
- 500 calorie = 2,092 joule
- 1000 calorie = 4,184 joule
Calorie to Joule conversion chart (both directions)
The chart below converts calorie to joule and joule to calorie side by side, so it works whichever way you need. 1 calorie = 4.184 joule, and 1 joule = 0.2390057 calorie.
| Calorie → Joule | Joule → Calorie |
|---|---|
| 0.25 cal = 1.046 J | 0.25 J = 0.05975143 cal |
| 0.5 cal = 2.092 J | 0.5 J = 0.1195029 cal |
| 1 cal = 4.184 J | 1 J = 0.2390057 cal |
| 2 cal = 8.368 J | 2 J = 0.4780115 cal |
| 3 cal = 12.552 J | 3 J = 0.7170172 cal |
| 4 cal = 16.736 J | 4 J = 0.9560229 cal |
| 5 cal = 20.92 J | 5 J = 1.195029 cal |
| 6 cal = 25.104 J | 6 J = 1.434034 cal |
| 7 cal = 29.288 J | 7 J = 1.67304 cal |
| 8 cal = 33.472 J | 8 J = 1.912046 cal |
| 9 cal = 37.656 J | 9 J = 2.151052 cal |
| 10 cal = 41.84 J | 10 J = 2.390057 cal |
| 12 cal = 50.208 J | 12 J = 2.868069 cal |
| 15 cal = 62.76 J | 15 J = 3.585086 cal |
| 20 cal = 83.68 J | 20 J = 4.780115 cal |
| 25 cal = 104.6 J | 25 J = 5.975143 cal |
| 30 cal = 125.52 J | 30 J = 7.170172 cal |
| 40 cal = 167.36 J | 40 J = 9.560229 cal |
| 50 cal = 209.2 J | 50 J = 11.95029 cal |
| 75 cal = 313.8 J | 75 J = 17.92543 cal |
| 100 cal = 418.4 J | 100 J = 23.90057 cal |
| 150 cal = 627.6 J | 150 J = 35.85086 cal |
| 200 cal = 836.8 J | 200 J = 47.80115 cal |
| 250 cal = 1,046 J | 250 J = 59.75143 cal |
| 500 cal = 2,092 J | 500 J = 119.5029 cal |
| 1000 cal = 4,184 J | 1000 J = 239.0057 cal |
Calorie vs Joule: which is bigger?
A calorie is the larger unit: one calorie equals 4.184 joules. Put another way, you need 4.184 joules to make a single calorie.
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 Joule? History, origin and usage
The joule is named after the English physicist James Prescott Joule (1818-1889), a Salford brewer’s son who, through painstaking experiments in the 1840s, measured the mechanical equivalent of heat and showed that work and heat are interchangeable forms of energy. The name was proposed by Wilhelm Siemens at an 1882 British Association meeting, and the joule was adopted as an international unit at the 1889 International Electrical Congress — just weeks before Joule himself died.
As the SI unit of energy, the joule underpins all of physics and engineering, measuring mechanical work, heat and electrical energy alike (one joule is also one watt-second). It appears on European food labels (usually as kilojoules), in battery specifications, and anywhere energy must be stated in coherent SI units.
One joule is roughly the energy needed to lift a small apple (about 100 grams) one metre against gravity, or the kinetic energy of a 56-gram tennis ball travelling about 6 m/s. Because one joule equals one newton-metre, the joule is dimensionally identical to the newton-metre of torque, yet the two describe different physical quantities.
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 Joule to other units
One joule (J) is equal to:
| 1 Joule equals | Unit |
|---|---|
| 1 N·m | Newton-metre |
| 0.001 kJ | Kilojoule |
| 0.000001 MJ | Megajoule |
| 0.0002777778 Wh | Watt-hour |
| 0.0000002777778 kWh | Kilowatt-hour |
| 0.0000000002777778 MWh | Megawatt-hour |
| 0.7375621 ft·lbf | Foot-pound |
| 6,241,509,000,000 MeV | Megaelectronvolt |
| 0.2390057 cal | Calorie |
| 0.0002390057 kcal | Kilocalorie |
| 0.0009478171 BTU | British Thermal Unit |
Tips for converting Calorie to Joule
- To go from calorie to joule, multiply by 4.184; to go back, divide by 4.184 (or multiply by 0.2390057).
- For a quick mental estimate, remember that 1 calorie ≈ 4.184 joule, so 10 calorie ≈ 41.84 joule.
- 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 Joule converter
Type a number into the Calorie field and the equivalent in Joule 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 Joule field to convert the other way (joule 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 = 4.184 J), 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-joule 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 joule are in 1 calorie?
- 1 calorie = 4.184 joule (J). To convert any number of calorie to joule, multiply by 4.184.
- How do I convert calorie to joule?
- Multiply the number of calorie by 4.184. For example, 10 calorie = 10 × 4.184 = 41.84 joule, and 25 calorie = 104.6 joule.
- How many calorie are in 1 joule?
- 1 joule = 0.2390057 calorie. So to convert joule back to calorie, multiply by 0.2390057.
- What is the formula to convert calorie to joule?
- joule = calorie × 4.184. The reverse formula is calorie = joule × 0.2390057.
- How much is 100 calorie in joule?
- 100 calorie = 418.4 joule. (And 1000 calorie = 4,184 joule.)
- Which is bigger, a calorie or a joule?
- A calorie is larger: 1 calorie = 4.184 joule.
- Is this calorie to joule converter accurate?
- Yes — every value is computed from the exact 4.184 J per cal factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
- Can I convert joule to calorie too?
- Yes. The converter works both ways — enter a value in either field. 1 joule = 0.2390057 calorie.