Convert Nail to Fathom
Convert nails to fathoms instantly. 1 nail = 0.03125 fathom — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Fathom to Nail converter for the reverse conversion.
Units explained
Nail
A nail is an Imperial unit of length equal to 2.25 inches (about 57.15 mm). It was historically used in the English cloth trade.
The nail derives from an English cloth-measure tradition dating to medieval times. Standardised at 2.25 inches (or 1/16 of a yard) through English customary practice and ratified by the 1959 International Yard and Pound Agreement.
Nails were historically used to measure cloth, particularly small pieces and ribbons. Rare in modern commerce but appears in historical textile literature and reproduction crafts.
Medieval English cloth-trade origin; standardised at 1/16 yard; fixed exactly at 0.05715 m via the 1959 International Yard and Pound Agreement.
Fathom
A fathom is an Imperial unit of length equal to 6 feet or exactly 1.8288 meters. It is used almost exclusively for measuring water depth in maritime contexts.
The fathom derives from the Old English word fæthm, meaning "the embracing arms" — the distance between the fingertips of a person's outstretched arms. Standardized at 6 feet in English maritime tradition.
Fathoms are used in nautical depth charts, scuba diving, oceanography, and maritime literature. Despite metrication efforts, fathoms remain common in English-language nautical charts and recreational diving.
Old English origin (predating 1066); standardized at 6 feet by English maritime tradition; fixed at 1.8288 m exactly via the 1959 International Yard and Pound Agreement.
Nail to Fathom conversion formula
The relationship between nails and fathoms:
To convert nails to fathoms, multiply the value in nails by 0.03125. To reverse, multiply fathoms by 32.
How to use this converter
Type a value into the calculator. The result in fathoms updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Fathom to Nail converter for the reverse direction.
Step-by-step: convert nails to fathoms
- Write down the value in nails (nail).
- Multiply that value by the factor 0.03125.
- The product is the equivalent value in fathoms (ftm).
- To reverse, multiply the fathom value by 32.
Worked examples
Example 1 — Convert 1 nail to ftm:
1 × 0.03125 = 0.03125 ftm
Example 2 — Convert 100 nail to ftm:
100 × 0.03125 = 3.125 ftm
Real-world example — Children's height milestones
A 150-nail-tall child measures a value in fathoms that's commonly used for theme-park ride height requirements when travelling between countries that use different measurement units.
150 nail × 0.03125 = 4.6875 ftm
Real-world example — Body height conversion
You enter your height as 180 nails into an international job or visa application. The form then asks for the same value in fathoms — converting between these adjacent units is one of the most-used length conversions globally.
180 nail × 0.03125 = 5.625 ftm
Real-world example — Furniture and large objects
A 72-nail piece of furniture converts to a value in fathoms that's easier to mentally compare with room dimensions. This is the typical workflow when shopping internationally and product specs use a different unit than your room measurements.
72 nail × 0.03125 = 2.25 ftm
Nail to Fathom conversion table
Standard reference values for converting nails to fathoms:
| Nail [nail] | Fathom [ftm] |
|---|---|
| 0.01 | 0.0003125 |
| 0.1 | 0.003125 |
| 1 | 0.03125 |
| 2 | 0.0625 |
| 3 | 0.09375 |
| 4 | 0.125 |
| 5 | 0.15625 |
| 10 | 0.3125 |
| 20 | 0.625 |
| 30 | 0.9375 |
| 40 | 1.25 |
| 50 | 1.5625 |
| 100 | 3.125 |
| 500 | 15.625 |
| 1000 | 31.25 |
Frequently asked questions
How many fathoms is 1 nail?
How do I convert nails to fathoms?
How do I convert fathoms back to nails?
How many fathoms is 100 nails?
Popular length unit conversions
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Metric / SI (4 units)
Imperial / US Customary (26 units)
Sources & references
Conversion factor (1 nail = 0.03125 ftm) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.