Convert Fathom to Angstrom (ftm → Å)
The fathom is the traditional marine depth unit, equal to six feet, used in nautical charts and diving manuals.
Fathom to Angstrom Conversion Table
10 common values| Fathom | Angstrom |
|---|---|
| 1 ftm | 18,288,000,000 Å |
| 5 ftm | 91,440,000,000 Å |
| 10 ftm | 182,880,000,000 Å |
| 25 ftm | 457,200,000,000 Å |
| 50 ftm | 914,400,000,000 Å |
| 100 ftm | 1,828,800,000,000 Å |
| 250 ftm | 4,572,000,000,000 Å |
| 500 ftm | 9,144,000,000,000 Å |
| 1,000 ftm | 18,288,000,000,000 Å |
| 5,000 ftm | 91,440,000,000,000 Å |
How to Convert Fathom to Angstrom Manually
Step by StepConverting fathoms to angstroms is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.
- 1Take your value in fathomsStart with the number of fathoms (ftm) you want to convert.
- 2Multiply by 18,288,000,000The conversion factor from ftm to Å is 18,288,000,000. Multiply your value by this number.
- 3Read the result in angstromsThe result is your value in angstroms (Å).
Formula
Multiply the value in fathoms by 18,288,000,000. For the reverse direction, multiply by 5.468 × 10^-11.
Å = ftm × 18,288,000,000ftm = Å × 5.468 × 10^-11Tips
Use these in everyday conversions- 1 fathom = 2 yards = 6 feet = 1.8288 m.
- Modern charts use metres internationally; fathoms are mostly historical.
- The word "fathom" comes from Old English for "outstretched arms" — originally the span of an adult's arms.
Common Mistakes
Avoid these- Reading a modern chart that uses metres as if it were fathoms — a factor-of-1.83 depth error.
- Confusing fathoms with feet on mixed-unit charts.
- Assuming all US charts still use fathoms — NOAA has largely migrated to metres.
About Fathom and Angstrom
What is the Fathom?
The fathom equals exactly 1.8288 meters or 6 feet and is the traditional marine depth unit. The word derives from the Old English 'fæðm,' meaning the span of outstretched arms — historically the distance a sailor could measure rope by stretching it from fingertip to fingertip. Used since antiquity for sounding water depth (lowering a weighted line and counting fathom marks), the fathom remains common in nautical charts, diving manuals, and marine literature. Famous from Mark Twain's pen name (a riverboat lead's call meaning 'safe water,' 2 fathoms or 12 feet) and Shakespeare's 'full fathom five,' the unit retains cultural resonance. Modern oceanographic science prefers the meter, but the fathom persists in fishing, recreational diving, and historical maritime contexts. The fathom relates to the foot (1 fathom = 6 ft) and the yard (1 fathom = 2 yd).
- Water depth on older US nautical charts
- Maritime literature and historical navigation
- Sport diving and scuba depth references in the US
A "mark twain" reading — made famous by the Mississippi riverboats — meant 2 fathoms (3.66 m) of water, the minimum safe depth.
What is the Angstrom?
The angstrom equals exactly 0.1 nanometers or 10⁻¹⁰ meters and is the historical unit for atomic and molecular dimensions. Named after Swedish physicist Anders Jonas Ångström (1814–1874), who used it to chart the wavelengths of solar spectral lines, the unit was widely adopted in spectroscopy, crystallography, and chemistry. The diameter of a hydrogen atom is about 1 Å, and visible light wavelengths range from 4,000 to 7,000 Å. While the SI system officially recommends nanometers (10 Å = 1 nm), the angstrom remains common in older physics and chemistry literature, X-ray diffraction studies, and crystal structure data. The symbol Å uses a special character with a circle above the A. The angstrom is one of the few non-SI units still routinely used in scientific publications, particularly in solid-state physics.
- X-ray crystallography and protein structure
- Chemical bond length measurement
- Atomic physics and spectroscopy
A water molecule is about 1 Å across. The covalent bond in H₂ is 0.74 Å. X-ray wavelengths are 0.1–100 Å.