An angstrom is 1e-10 meters.
Angstroms to Femtometers Converter — A to fm
Convert Angstrom (A) to Femtometer (fm) using the exact conversion factor (1 angstrom = 100,000 femtometer). See the formula, worked examples, conversion table, history, and common uses.
Angstroms to Femtometers converter
Converter
Length Converter
Convert SI, imperial, US customary, astronomical, scientific, and historical length units.
Context values
Some unit families need one extra value for a physically accurate result.
Femtometer is 1e-15 meter units.
Result = input x 1e-10 / 1e-15.
Length uses the meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Angstroms to Femtometers
Angstrom and Femtometer both measure length. Angstrom is most often used for atomic and ionic radii in chemistry.
Formula
femtometers = angstroms × 100000
This factor comes from each unit's defined relationship to the category's base unit: 1 angstrom equals 1e-10 base units, and 1 femtometer equals 1e-15 base units, so dividing one by the other gives the direct angstrom-to-femtometer factor of 100000.
Simple example
1 A × 100000 = 100,000 fm
1 angstrom = 100,000 femtometers.
Real-world example
10 A × 100000 = 1,000,000 fm
10 angstroms = 1,000,000 femtometers.
Conversion table
| Angstrom (A) | Femtometer (fm) |
|---|---|
| 1 A | 100,000 fm |
| 5 A | 500,000 fm |
| 10 A | 1,000,000 fm |
| 21.0975 A | 2,109,750 fm |
| 42.195 A | 4,219,500 fm |
| 100 A | 10,000,000 fm |
Reverse conversion: Femtometer to Angstrom
1 fm × 0.00001 = 0.00001 A
1 femtometer = 0.00001 angstroms.
angstroms = femtometers × 0.00001
For a page dedicated to this direction, see Femtometer to Angstrom.
Understanding the Angstrom
Angstrom (A) measures length. Equal to exactly 10⁻¹⁰ meters (0.1 nanometers) — a scale convenient for describing atomic radii, bond lengths, and crystal structures. It is classified as a non-SI unit, still common in chemistry and crystallography.
Where it's used: Widely used internationally in chemistry, crystallography, and atomic/molecular physics
Uses of the Angstrom today
- Atomic and ionic radii in chemistry
- Chemical bond-length measurements
- X-ray crystallography and wavelength measurements
History of the Angstrom
The angstrom is named after Anders Jonas Ångström (1814–1874), a Swedish physicist and one of the founders of spectroscopy, who used the unit in his 1868 atlas of the solar spectrum.
Historical origin. Angstrom was not the invention of a single named person; it developed through the process described above.
Understanding the Femtometer (fm)
Femtometer is 1e-15 meter units.
Angstrom — sources
- NIST Guide to the SI, Appendix B — Lists the angstrom among non-SI units still in use with an exact SI equivalence.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many femtometers are in 1 angstrom?
1 angstrom equals 100,000 femtometers, using the exact defined conversion factor rather than an estimate.
How do I convert angstrom to femtometer?
Multiply the angstrom value by 100000. The converter above does this instantly to whatever precision you set.
How do I convert femtometer back to angstrom?
Use the reverse factor: 1 femtometer equals 0.00001 angstroms. You can also use the swap control in the converter above to flip the direction instantly.
What is a angstrom?
Angstrom (A) measures length. Equal to exactly 10⁻¹⁰ meters (0.1 nanometers) — a scale convenient for describing atomic radii, bond lengths, and crystal structures. It is classified as a non-SI unit, still common in chemistry and crystallography.
What is a femtometer?
Femtometer (fm) is a unit of length.
Is the angstrom to femtometer conversion exact?
Yes. Equal to exactly 10⁻¹⁰ meters (0.1 nanometers) — a scale convenient for describing atomic radii, bond lengths, and crystal structures. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
Where is the angstrom still used today?
Widely used internationally in chemistry, crystallography, and atomic/molecular physics