A femtojoule (fJ) is a metric-prefixed unit of energy equal to 10-15 joules, a fraction of a single joule, using the SI femto prefix.
Femtojoules to Rontojoules
Convert Femtojoule (fJ) to Rontojoule (rJ) 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 femtojoules (fJ) to rontojoules (rJ) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A rontojoule (rJ) is a metric-prefixed unit of energy equal to 10-27 joules, a fraction of a single joule, using the SI ronto prefix.
rJ = fJ × 1000000000000
Results update instantly for Femtojoules to Rontojoules conversions.
Reserved above the conversion cards and below the converter.
Formula
rJ = fJ × 1000000000000
fJ = rJ × 1.000000000e-12
Conversion table
| 1 fJ | 1.000000e+12 rJ |
| 5 fJ | 5.000000e+12 rJ |
| 10 fJ | 1.000000e+13 rJ |
| 20 fJ | 2.000000e+13 rJ |
| 50 fJ | 5.000000e+13 rJ |
| 100 fJ | 1.000000e+14 rJ |
| 500 fJ | 5.000000e+14 rJ |
| 1000 fJ | 1.000000e+15 rJ |
Related conversions
Reserved between the cards and the FAQ so the page stays balanced.
How the formula works
Both femtojoule and rontojoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in femtojoules by 1000000000000 to get rontojoules. To reverse the conversion, multiply a rontojoule value by 1.000000000e-12 to get back to femtojoules.
Frequently asked questions
What is Femtojoule (fJ)?
A femtojoule (fJ) is a metric-prefixed unit of energy equal to 10-15 joules, a fraction of a single joule, using the SI femto prefix.
What is Rontojoule (rJ)?
A rontojoule (rJ) is a metric-prefixed unit of energy equal to 10-27 joules, a fraction of a single joule, using the SI ronto prefix.
How do I convert femtojoules to rontojoules?
Multiply the femtojoule value by 1000000000000 to get the equivalent in rontojoules. For example, 5 fJ × 1000000000000 = 5.000000e+12 rJ.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 1000000000000 is an exact, non-rounded value.
Can I convert rontojoules back to femtojoules?
Yes. Divide the rontojoule value by 1000000000000, or multiply it by 1.000000000e-12, to get femtojoules.
Reserved between the FAQ and the article so the page stays balanced.
About converting femtojoules to rontojoules
A femtojoule (fJ) is a metric-prefixed unit of energy equal to 10-15 joules, a fraction of a single joule, using the SI femto prefix. A rontojoule (rJ) is a metric-prefixed unit of energy equal to 10-27 joules, a fraction of a single joule, using the SI ronto prefix.
Use this calculator to move between femtojoules and rontojoules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.