A millijoule (mJ) is a metric-prefixed unit of energy equal to 10-3 joules, a fraction of a single joule, using the SI milli prefix.
Millijoules to Femtojoules
Convert Millijoule (mJ) to Femtojoule (fJ) instantly with an exact formula, conversion table, and FAQ.
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Convert millijoules (mJ) to femtojoules (fJ) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
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.
fJ = mJ × 1000000000000
Results update instantly for Millijoules to Femtojoules conversions.
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Formula
fJ = mJ × 1000000000000
mJ = fJ × 1.000000000e-12
Conversion table
| 1 mJ | 1.000000e+12 fJ |
| 5 mJ | 5.000000e+12 fJ |
| 10 mJ | 1.000000e+13 fJ |
| 20 mJ | 2.000000e+13 fJ |
| 50 mJ | 5.000000e+13 fJ |
| 100 mJ | 1.000000e+14 fJ |
| 500 mJ | 5.000000e+14 fJ |
| 1000 mJ | 1.000000e+15 fJ |
Related conversions
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How the formula works
Both millijoule and femtojoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in millijoules by 1000000000000 to get femtojoules. To reverse the conversion, multiply a femtojoule value by 1.000000000e-12 to get back to millijoules.
Frequently asked questions
What is Millijoule (mJ)?
A millijoule (mJ) is a metric-prefixed unit of energy equal to 10-3 joules, a fraction of a single joule, using the SI milli prefix.
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.
How do I convert millijoules to femtojoules?
Multiply the millijoule value by 1000000000000 to get the equivalent in femtojoules. For example, 5 mJ × 1000000000000 = 5.000000e+12 fJ.
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 femtojoules back to millijoules?
Yes. Divide the femtojoule value by 1000000000000, or multiply it by 1.000000000e-12, to get millijoules.
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About converting millijoules to femtojoules
A millijoule (mJ) is a metric-prefixed unit of energy equal to 10-3 joules, a fraction of a single joule, using the SI milli prefix. 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.
Use this calculator to move between millijoules and femtojoules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.