Convert Rod to Fathom
Convert rods to fathoms instantly. 1 rod = 2.75 fathom — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Fathom to Rod converter for the reverse conversion.
Units explained
Rod
A rod is an Imperial unit of length equal to 16.5 feet (about 5.03 m). It is also called a perch or pole. Used historically in English and American land surveying.
The rod derives from medieval English land-surveying practice. Standardised at 16.5 feet (= 25 links of a surveyor's chain = 1/4 chain) by Edmund Gunter in 1620.
Rods are the standard unit in legacy US public-land-survey records, where lot dimensions are typically expressed in rods and chains. Modern surveyors generally use feet or meters but legacy deeds remain in rods.
Defined by Edmund Gunter in 1620 as 16.5 feet via the chain-based survey system; became exact 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.
Rod to Fathom conversion formula
The relationship between rods and fathoms:
To convert rods to fathoms, multiply the value in rods by 2.75. To reverse, multiply fathoms by 0.3636363636.
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 Rod converter for the reverse direction.
Step-by-step: convert rods to fathoms
- Write down the value in rods (rd).
- Multiply that value by the factor 2.75.
- The product is the equivalent value in fathoms (ftm).
- To reverse, multiply the fathom value by 0.3636363636.
Worked examples
Example 1 — Convert 1 rd to ftm:
1 × 2.75 = 2.75 ftm
Example 2 — Convert 100 rd to ftm:
100 × 2.75 = 275 ftm
Real-world example — Reference scenario in case of fallback
Conversion between human-scale length units is the everyday workflow of architecture, athletics, and apparel design — three of the most common contexts that span metric and imperial systems.
1 rd × 2.75 = 2.75 ftm
Real-world example — Adult height conversion
A 1.8-rod-tall person measures a value in fathoms that converts the height to the unit favoured by American forms, schools, or driver's licences. This is daily routine for anyone living between metric and imperial systems.
1.8 rd × 2.75 = 4.95 ftm
Real-world example — Fabric purchase length
Two rods of fabric equals a value in fathoms essential for tailors and textile buyers sourcing material from international suppliers that quote in different units.
2 rd × 2.75 = 5.5 ftm
Rod to Fathom conversion table
Standard reference values for converting rods to fathoms:
| Rod [rd] | Fathom [ftm] |
|---|---|
| 0.01 | 0.0275 |
| 0.1 | 0.275 |
| 1 | 2.75 |
| 2 | 5.5 |
| 3 | 8.25 |
| 4 | 11 |
| 5 | 13.75 |
| 10 | 27.5 |
| 20 | 55 |
| 30 | 82.5 |
| 40 | 110 |
| 50 | 137.5 |
| 100 | 275 |
| 500 | 1375 |
| 1000 | 2750 |
Frequently asked questions
How many fathoms is 1 rod?
How do I convert rods to fathoms?
How do I convert fathoms back to rods?
How many fathoms is 100 rods?
Popular length unit conversions
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Metric / SI (4 units)
Imperial / US Customary (26 units)
Sources & references
Conversion factor (1 rd = 2.75 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.