Convert Joule to Calorie
1 joule = 0.2390057 calorie (cal). For example, 10 joule = 2.390057 calorie and 100 joule = 23.90057 calorie. Type any value below to convert joule to calorie both ways — it runs entirely in your browser.
Quick answer: Joule to Calorie
1 Joule = 0.2390057 Calorie (J → cal). To convert joule to calorie, multiply by 0.2390057. To convert calorie to joule, multiply by 4.184. 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 joule-to-calorie questions.
How to convert Joule to Calorie
To convert joule to calorie, multiply the number of joule by the conversion factor 0.2390057, because 1 J = 0.2390057 cal. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 cal = 4.184 J, so you divide by 0.2390057 (or multiply by 4.184) to turn calorie back into joule.
cal = J × 0.2390057 ·
J = cal × 4.184
- Write down the value you want to convert, in joule.
- Multiply it by 0.2390057.
- The result is the same area/length/quantity expressed in calorie.
Joule to Calorie — worked examples
Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 joule is 1.195029 calorie because 5 J × 0.2390057 = 1.195029 cal.
| Joule | Calculation | Calorie |
|---|---|---|
| 1 J | 1 J × 0.2390057 = 0.2390057 cal | 0.2390057 cal |
| 2 J | 2 J × 0.2390057 = 0.4780115 cal | 0.4780115 cal |
| 3 J | 3 J × 0.2390057 = 0.7170172 cal | 0.7170172 cal |
| 5 J | 5 J × 0.2390057 = 1.195029 cal | 1.195029 cal |
| 7 J | 7 J × 0.2390057 = 1.67304 cal | 1.67304 cal |
| 10 J | 10 J × 0.2390057 = 2.390057 cal | 2.390057 cal |
| 12 J | 12 J × 0.2390057 = 2.868069 cal | 2.868069 cal |
| 15 J | 15 J × 0.2390057 = 3.585086 cal | 3.585086 cal |
| 20 J | 20 J × 0.2390057 = 4.780115 cal | 4.780115 cal |
| 25 J | 25 J × 0.2390057 = 5.975143 cal | 5.975143 cal |
| 50 J | 50 J × 0.2390057 = 11.95029 cal | 11.95029 cal |
| 100 J | 100 J × 0.2390057 = 23.90057 cal | 23.90057 cal |
Common Joule to Calorie conversions
These are the joule-to-calorie values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:
- 1 joule = 0.2390057 calorie
- 2 joule = 0.4780115 calorie
- 2.5 joule = 0.5975143 calorie
- 3 joule = 0.7170172 calorie
- 4 joule = 0.9560229 calorie
- 5 joule = 1.195029 calorie
- 6 joule = 1.434034 calorie
- 7 joule = 1.67304 calorie
- 8 joule = 1.912046 calorie
- 9 joule = 2.151052 calorie
- 10 joule = 2.390057 calorie
- 12 joule = 2.868069 calorie
- 15 joule = 3.585086 calorie
- 20 joule = 4.780115 calorie
- 25 joule = 5.975143 calorie
- 30 joule = 7.170172 calorie
- 50 joule = 11.95029 calorie
- 75 joule = 17.92543 calorie
- 100 joule = 23.90057 calorie
- 200 joule = 47.80115 calorie
- 500 joule = 119.5029 calorie
- 1000 joule = 239.0057 calorie
Joule to Calorie conversion chart (both directions)
The chart below converts joule to calorie and calorie to joule side by side, so it works whichever way you need. 1 joule = 0.2390057 calorie, and 1 calorie = 4.184 joule.
| Joule → Calorie | Calorie → Joule |
|---|---|
| 0.25 J = 0.05975143 cal | 0.25 cal = 1.046 J |
| 0.5 J = 0.1195029 cal | 0.5 cal = 2.092 J |
| 1 J = 0.2390057 cal | 1 cal = 4.184 J |
| 2 J = 0.4780115 cal | 2 cal = 8.368 J |
| 3 J = 0.7170172 cal | 3 cal = 12.552 J |
| 4 J = 0.9560229 cal | 4 cal = 16.736 J |
| 5 J = 1.195029 cal | 5 cal = 20.92 J |
| 6 J = 1.434034 cal | 6 cal = 25.104 J |
| 7 J = 1.67304 cal | 7 cal = 29.288 J |
| 8 J = 1.912046 cal | 8 cal = 33.472 J |
| 9 J = 2.151052 cal | 9 cal = 37.656 J |
| 10 J = 2.390057 cal | 10 cal = 41.84 J |
| 12 J = 2.868069 cal | 12 cal = 50.208 J |
| 15 J = 3.585086 cal | 15 cal = 62.76 J |
| 20 J = 4.780115 cal | 20 cal = 83.68 J |
| 25 J = 5.975143 cal | 25 cal = 104.6 J |
| 30 J = 7.170172 cal | 30 cal = 125.52 J |
| 40 J = 9.560229 cal | 40 cal = 167.36 J |
| 50 J = 11.95029 cal | 50 cal = 209.2 J |
| 75 J = 17.92543 cal | 75 cal = 313.8 J |
| 100 J = 23.90057 cal | 100 cal = 418.4 J |
| 150 J = 35.85086 cal | 150 cal = 627.6 J |
| 200 J = 47.80115 cal | 200 cal = 836.8 J |
| 250 J = 59.75143 cal | 250 cal = 1,046 J |
| 500 J = 119.5029 cal | 500 cal = 2,092 J |
| 1000 J = 239.0057 cal | 1000 cal = 4,184 J |
Joule vs Calorie: 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 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.
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.
Convert 1 Joule to other units
It can help to see a joule next to the other units it is commonly compared with. 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 |
Convert 1 Calorie to other units
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 |
Tips for converting Joule to Calorie
- To go from joule to calorie, multiply by 0.2390057; to go back, divide by 0.2390057 (or multiply by 4.184).
- For a quick mental estimate, remember that 1 joule ≈ 0.2390057 calorie, so 10 joule ≈ 2.390057 calorie.
- 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 Joule to Calorie converter
Type a number into the Joule field and the equivalent in Calorie 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 Calorie field to convert the other way (calorie to joule). 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 J = 0.2390057 cal), 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 joule-to-calorie 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 calorie are in 1 joule?
- 1 joule = 0.2390057 calorie (cal). To convert any number of joule to calorie, multiply by 0.2390057.
- How do I convert joule to calorie?
- Multiply the number of joule by 0.2390057. For example, 10 joule = 10 × 0.2390057 = 2.390057 calorie, and 25 joule = 5.975143 calorie.
- How many joule are in 1 calorie?
- 1 calorie = 4.184 joule. So to convert calorie back to joule, multiply by 4.184.
- What is the formula to convert joule to calorie?
- calorie = joule × 0.2390057. The reverse formula is joule = calorie × 4.184.
- How much is 100 joule in calorie?
- 100 joule = 23.90057 calorie. (And 1000 joule = 239.0057 calorie.)
- Which is bigger, a joule or a calorie?
- A calorie is larger: 1 calorie = 4.184 joule.
- Is this joule to calorie converter accurate?
- Yes — every value is computed from the exact 0.2390057 cal per J factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
- Can I convert calorie to joule too?
- Yes. The converter works both ways — enter a value in either field. 1 calorie = 4.184 joule.