Instant · Precise · Universal
32 units available
6 categories total
To convert fm to meters: multiply by 10⁻¹⁵. To convert meters to fm: multiply by 10¹⁵.
1 fm = 10⁻¹⁵ m = 1,000 am = 10⁻⁶ nm. One meter equals 10¹⁵ femtometers.
For example, 1 Femtometer (fm) = 3.240756e-32 Parsec (pc).
| Femtometer (fm) | Parsec (pc) |
|---|---|
| 0.1 | 3.240756e-33 |
| 0.5 | 1.620378e-32 |
| 1 | 3.240756e-32 |
| 2 | 6.481511e-32 |
| 5 | 1.620378e-31 |
| 10 | 3.240756e-31 |
| 25 | 8.101889e-31 |
| 50 | 1.620378e-30 |
| 100 | 3.240756e-30 |
| 500 | 1.620378e-29 |
| 1000 | 3.240756e-29 |
The femtometer is a unit of length equal to 10⁻¹⁵ meters, commonly used to measure the size of atomic nuclei.
1 fm = 10⁻¹⁵ m = 1,000 am = 10⁻⁶ nm. One meter equals 10¹⁵ femtometers.
To convert fm to meters: multiply by 10⁻¹⁵. To convert meters to fm: multiply by 10¹⁵.
Describing the size of protons (~0.87 fm radius) and nuclear diameters (1–15 fm depending on the element).
A proton's charge radius is approximately 0.87 fm. The diameter of a uranium-238 nucleus is about 15 fm.
Confusing femtometers with nanometers — a femtometer is one million times smaller than a nanometer.
Remember: atoms are ~0.1 nm, but nuclei are ~1–10 fm — nuclei are about 100,000 times smaller than the whole atom.
The parsec is an astronomical unit of length defined as the distance at which one astronomical unit subtends an angle of one arcsecond.
1 pc = 3.0857 × 10¹⁶ m = 3.2616 ly = 206,265 AU ≈ 30.857 trillion km.
To convert pc to light-years: multiply by 3.2616. To convert pc to AU: multiply by 206,265.
Stellar catalogs, galaxy surveys, and cosmological distance calculations.
No known star is within 1 parsec of the Sun. Proxima Centauri is 1.30 pc away, making it the nearest star.
Pronouncing or interpreting 'parsec' as a unit of time (famously misused in Star Wars). It is strictly a distance unit.
The parsec is defined geometrically: if a star's parallax (apparent shift over 6 months) is 1 arcsecond, it's 1 pc away.



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