Femtometer to Astronomical Unit Converter
Unit Converter
Instant · Precise · Universal
32 units available
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How to Convert Femtometer to Astronomical Unit
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) = 6.684587e-27 Astronomical Unit (AU).
Femtometer to Astronomical Unit — Common Values
| Femtometer (fm) | Astronomical Unit (AU) |
|---|---|
| 0.1 | 6.684587e-28 |
| 0.5 | 3.342294e-27 |
| 1 | 6.684587e-27 |
| 2 | 1.336917e-26 |
| 5 | 3.342294e-26 |
| 10 | 6.684587e-26 |
| 25 | 1.671147e-25 |
| 50 | 3.342294e-25 |
| 100 | 6.684587e-25 |
| 500 | 3.342294e-24 |
| 1000 | 6.684587e-24 |
About Femtometer (fm)
Definition
The femtometer is a unit of length equal to 10⁻¹⁵ meters, commonly used to measure the size of atomic nuclei.
Mathematical Relationship
1 fm = 10⁻¹⁵ m = 1,000 am = 10⁻⁶ nm. One meter equals 10¹⁵ femtometers.
Conversion Formula
To convert fm to meters: multiply by 10⁻¹⁵. To convert meters to fm: multiply by 10¹⁵.
Practical Applications
Describing the size of protons (~0.87 fm radius) and nuclear diameters (1–15 fm depending on the element).
Interesting Facts
A proton's charge radius is approximately 0.87 fm. The diameter of a uranium-238 nucleus is about 15 fm.
Common Mistakes
Confusing femtometers with nanometers — a femtometer is one million times smaller than a nanometer.
Educational Tips
Remember: atoms are ~0.1 nm, but nuclei are ~1–10 fm — nuclei are about 100,000 times smaller than the whole atom.
About Astronomical Unit (AU)
Definition
The astronomical unit is a unit of length approximating the mean Earth-Sun distance, defined as exactly 149,597,870,700 meters.
Mathematical Relationship
1 AU = 149,597,870,700 m ≈ 149.598 Gm ≈ 499 light-seconds ≈ 8.317 light-minutes.
Conversion Formula
To convert AU to km: multiply by 149,597,870.7. To convert AU to light-years: divide by 63,241.
Practical Applications
Spacecraft mission planning, expressing planetary orbit sizes, and solar system scale models.
Interesting Facts
Light takes about 8 minutes and 20 seconds to travel 1 AU. Mars is about 1.52 AU from the Sun, Jupiter about 5.2 AU.
Common Mistakes
Thinking the AU is the exact Earth-Sun distance — Earth's actual distance varies from ~147 to ~152 Gm over the year due to orbital eccentricity.
Educational Tips
AU makes the solar system manageable: Mercury ≈ 0.39 AU, Venus ≈ 0.72, Earth = 1, Mars ≈ 1.52, Jupiter ≈ 5.2, Saturn ≈ 9.5.