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 Kilojoules
Convert Yoctojoule (yJ) to Kilojoule (kJ) instantly with an exact formula, conversion table, and FAQ.
Reserved for a responsive leaderboard above the conversion details.
Professional calculator style
World-scale conversion engine
30+ categories
6,500+ units
Instant results
Offline ready
Energy calculator
Energy Converter
Convert yoctojoules (yJ) to kilojoules (kJ) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A kilojoule (kJ) equals 1,000 joules and is commonly used on nutrition labels outside the United States.
kJ = yJ × 1.000000000e-27
Results update instantly for Yoctojoules to Kilojoules conversions.
Reserved above the conversion cards and below the converter.
Formula
kJ = yJ × 1.000000000e-27
yJ = kJ × 1.000000000e+27
Conversion table
| 1 yJ | 1.000000e-27 kJ |
| 5 yJ | 5.000000e-27 kJ |
| 10 yJ | 1.000000e-26 kJ |
| 20 yJ | 2.000000e-26 kJ |
| 50 yJ | 5.000000e-26 kJ |
| 100 yJ | 1.000000e-25 kJ |
| 500 yJ | 5.000000e-25 kJ |
| 1000 yJ | 1.000000e-24 kJ |
Related conversions
Reserved between the cards and the FAQ so the page stays balanced.
How the formula works
Both yoctojoule and kilojoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in yoctojoules by 1.000000000e-27 to get kilojoules. To reverse the conversion, multiply a kilojoule value by 1.000000000e+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 Kilojoule (kJ)?
A kilojoule (kJ) equals 1,000 joules and is commonly used on nutrition labels outside the United States.
How do I convert yoctojoules to kilojoules?
Multiply the yoctojoule value by 1.000000000e-27 to get the equivalent in kilojoules. For example, 5 yJ × 1.000000000e-27 = 5.000000e-27 kJ.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 1.000000000e-27 is an exact, non-rounded value.
Can I convert kilojoules back to yoctojoules?
Yes. Divide the kilojoule value by 1.000000000e-27, or multiply it by 1.000000000e+27, to get yoctojoules.
Reserved between the FAQ and the article so the page stays balanced.
About converting yoctojoules to kilojoules
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 kilojoule (kJ) equals 1,000 joules and is commonly used on nutrition labels outside the United States.
Use this calculator to move between yoctojoules and kilojoules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.