A yoctojoule (yJ) is a metric-prefixed unit of energy equal to 10-24 joules, a fraction of a single joule, using the SI yocto prefix.
Yoctojoules to Kilocalories
Convert Yoctojoule (yJ) to Kilocalorie (kcal) instantly with an exact formula, conversion table, and FAQ.
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Convert yoctojoules (yJ) to kilocalories (kcal) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A kilocalorie (kcal) equals 1,000 small calories and is the unit behind the food "Calorie" shown on nutrition labels.
kcal = yJ × 2.390057361e-28
Results update instantly for Yoctojoules to Kilocalories conversions.
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Formula
kcal = yJ × 2.390057361e-28
yJ = kcal × 4.184000000e+27
Conversion table
| 1 yJ | 2.390057e-28 kcal |
| 5 yJ | 1.195029e-27 kcal |
| 10 yJ | 2.390057e-27 kcal |
| 20 yJ | 4.780115e-27 kcal |
| 50 yJ | 1.195029e-26 kcal |
| 100 yJ | 2.390057e-26 kcal |
| 500 yJ | 1.195029e-25 kcal |
| 1000 yJ | 2.390057e-25 kcal |
Related conversions
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How the formula works
Both yoctojoule and kilocalorie measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in yoctojoules by 2.390057361e-28 to get kilocalories. To reverse the conversion, multiply a kilocalorie value by 4.184000000e+27 to get back to yoctojoules.
Frequently asked questions
What is Yoctojoule (yJ)?
A yoctojoule (yJ) is a metric-prefixed unit of energy equal to 10-24 joules, a fraction of a single joule, using the SI yocto prefix.
What is Kilocalorie (kcal)?
A kilocalorie (kcal) equals 1,000 small calories and is the unit behind the food "Calorie" shown on nutrition labels.
How do I convert yoctojoules to kilocalories?
Multiply the yoctojoule value by 2.390057361e-28 to get the equivalent in kilocalories. For example, 5 yJ × 2.390057361e-28 = 1.195029e-27 kcal.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 2.390057361e-28 is an exact, non-rounded value.
Can I convert kilocalories back to yoctojoules?
Yes. Divide the kilocalorie value by 2.390057361e-28, or multiply it by 4.184000000e+27, to get yoctojoules.
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About converting yoctojoules to kilocalories
A yoctojoule (yJ) is a metric-prefixed unit of energy equal to 10-24 joules, a fraction of a single joule, using the SI yocto prefix. A kilocalorie (kcal) equals 1,000 small calories and is the unit behind the food "Calorie" shown on nutrition labels.
Use this calculator to move between yoctojoules and kilocalories accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.