Femtometer is 1e-15 meter units.
Femtometers to Angstroms Converter — fm to A
Convert Femtometer (fm) to Angstrom (A) using the exact conversion factor (1 femtometer = 0.00001 angstrom). See the formula, worked examples, conversion table, history, and common uses.
Femtometers to Angstroms 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.
An angstrom is 1e-10 meters.
Result = input x 1e-15 / 1e-10.
Length uses the meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Femtometers to Angstroms
Femtometer and Angstrom both measure length. Specifically: Femtometer is 1e-15 meter units, and an angstrom is 1e-10 meters.
Formula
angstroms = femtometers × 0.00001
This factor comes from each unit's defined relationship to the category's base unit: 1 femtometer equals 1e-15 base units, and 1 angstrom equals 1e-10 base units, so dividing one by the other gives the direct femtometer-to-angstrom factor of 0.00001.
Simple example
1 fm × 0.00001 = 0.00001 A
1 femtometer = 0.00001 angstroms.
Real-world example
10 fm × 0.00001 = 0.0001 A
10 femtometers = 0.0001 angstroms.
Conversion table
| Femtometer (fm) | Angstrom (A) |
|---|---|
| 1 fm | 0.00001 A |
| 5 fm | 0.00005 A |
| 10 fm | 0.0001 A |
| 21.0975 fm | 0.000210975 A |
| 42.195 fm | 0.00042195 A |
| 100 fm | 0.001 A |
Reverse conversion: Angstrom to Femtometer
0.00001 A × 100000 = 1 fm
0.00001 angstroms = 1 femtometer.
femtometers = angstroms × 100000
For a page dedicated to this direction, see Angstrom to Femtometer.
Understanding the Femtometer (fm)
Femtometer is 1e-15 meter units.
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.
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 angstroms are in 1 femtometer?
1 femtometer equals 0.00001 angstroms, using the exact defined conversion factor rather than an estimate.
How do I convert femtometer to angstrom?
Multiply the femtometer value by 0.00001. The converter above does this instantly to whatever precision you set.
How do I convert angstrom back to femtometer?
Use the reverse factor: 1 angstrom equals 100,000 femtometers. You can also use the swap control in the converter above to flip the direction instantly.
What is a femtometer?
Femtometer (fm) is a unit of length.
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.
Is the femtometer to angstrom 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.