Calories to Joules Converter
Quick answer: To convert calories to joules, multiply by 4.184. For example, 10 cal is 41.84 J. One calorie equals 4.184 J.
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Use the Calories to Joules Converter
Calories to Joules formula and what each symbol means
J = cal × 4.184
| Symbol | Meaning |
|---|---|
| cal | Calorie |
| J | Joule |
Calories to Joules examples
1 cal
1 cal × 4.184 = 4.184 J.
10 cal
10 cal × 4.184 = 41.84 J.
100 cal
100 cal × 4.184 = 418.4 J.
Calories compared with Joules
One cal is 4.184 times as large as one J, so your number gets bigger when you convert calories to joules and smaller when you convert back. If the answer is not larger than what you typed, you divided instead of multiplying.
About calories and joules
Calorie (cal): The thermochemical calorie, exactly 4.184 joules. Joule (J): The SI unit of energy, one newton metre.
Where calories to joules conversions are used
Engineering and physics calculations usually work in joules. Food labels show kilocalories or kilojoules, and electricity bills use kilowatt-hours.
How to calculate Calories to Joules step by step
- Enter the value in cal (the starting unit).
- Multiply by 4.184, because 1 cal = 4.184 J.
- The product is the value in J. To go back, divide by 4.184 or multiply by 0.2390057.
Popular energy conversions
How to read your Calories to Joules result
Quick estimate: multiply by about 4.2 to get joules from calories; this is within 0.4% of the exact factor. The joule is the SI unit of energy.
| CALORIES | JOULES |
|---|---|
| 1 | 4.184 |
| 2 | 8.368 |
| 5 | 20.92 |
| 10 | 41.84 |
| 20 | 83.68 |
| 50 | 209.2 |
| 100 | 418.4 |
| 1,000 | 4,184 |
Joules to Calories: quick table
| JOULES | CALORIES |
|---|---|
| 1 | 0.2390057 |
| 5 | 1.195029 |
| 10 | 2.390057 |
| 25 | 5.975143 |
| 50 | 11.95029 |
| 100 | 23.90057 |
| 250 | 59.75143 |
| 500 | 119.5029 |
Common mistakes when calculating Calories to Joules
- Using different Btu definitions: this tool uses the International Table Btu of 1,055.05585262 J.
- Dividing when you should multiply: from cal to J multiply by 4.184; from J to cal divide by 4.184.
Calories to Joules FAQ
How many J are in 1 cal?
1 cal equals 4.184 J.
How many cal are in 1 J?
1 J equals 0.2390057 cal.
Is 1 cal = 4.184 J an exact conversion?
Yes. The calorie and the joule are both defined exactly in SI terms, so the ratio has no measurement uncertainty; 4.184 is just that ratio shown to 7 significant figures.
What is a joule (J)?
The SI unit of energy, one newton metre.
How can I estimate calories to joules in my head?
Quick estimate: multiply by about 4.2 to get joules from calories; this is within 0.4% of the exact factor.
What is 500 cal in joules?
500 cal = 2,092 J (since 500 × 4.184).
What is 15 cal in joules?
15 cal = 62.76 J (since 15 × 4.184).
What is 75 cal in joules?
75 cal = 313.8 J (since 75 × 4.184).
How many decimals should I keep when converting cal to J?
Match the precision of your original measurement. For example, 41.84 J rounds to 41.8 J at 3 significant figures; keep more digits only for engineering or scientific work.
More in Energy converters
- Calories to kWh Converter
- BTU to kJ Converter
- BTU to Kilocalories Converter
- Joules to BTU Converter
- BTU to Joules Converter
- BTU to Calories Converter
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Method, review and disclaimer
Edited by: Hemant Kumar and Anjita Rai, founders of ToolsVault (SEO and content professional, not a licensed adviser). Method: this tool runs in your browser using the formula shown on this page; the numbers you enter are not sent to our servers. Sources: NIST SP 811, Appendix B.8: conversion factors