One fathom is exactly 0.3636363636 rods, so converting fathoms to rods is a single multiplication. Enter any figure and the result appears as you type — the arithmetic runs in your browser, so nothing is sent anywhere.
Sixteen and a half feet, or a quarter of a chain; it survives in old deeds and fence estimating. Six feet, the traditional depth unit on marine charts.
The mil and the millimetre are not the same thing and are out by a factor of about forty. A mil is one thousandth of an inch — 0.0254 mm — and a spec sheet that quotes film thickness in mils means the small unit. British drawings write the same size as "thou". Below the calculator there is a step table for the values people look up most, and a second table putting real length figures into rods so the number you get has something to be compared against.
The formula
fathoms- The amount you are converting, in fathoms
0.363636363636- The exact number of rods in one fathom
rods- The converted result
How it works, step by step
- Enter the value in fathoms.
- It is multiplied by 0.363636363636, the exact factor between the two units.
- The answer is shown in rods, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
A door height: 1.11 ftm in rods
A door height comes to about 1.11 ftm. Multiplying by the factor: 1.11 × 0.363636 = 0.403636 rd. Dividing the answer back by 0.363636 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
A credit card’s long edge: 0.0468 ftm in rods
A credit card’s long edge comes to about 0.0468 ftm. Multiplying by the factor: 0.0468 × 0.363636 = 0.0170182 rd. Dividing the answer back by 0.363636 returns the figure you started with, which is the quickest way to check you have the factor the right way up.
How to read your score
Frequently asked questions
How many rods are in one fathom?
Exactly 0.363636363636. Every figure on this page is that one number multiplied by your input, so the only rounding is at the display step.
What is the formula to convert fathoms to rods?
rods = fathoms × 0.363636363636. Reversed, fathoms = rods ÷ 0.363636363636, which is the same as multiplying by 2.75.
Which is the bigger unit, the fathom or the rod?
The rod. One fathom is only 0.363636 of a rod, so it takes 2.75 fathoms to make one rod.
What does this quantity actually measure?
Both units measure length. That is why a single factor is enough: there is no temperature offset and no material property involved, unlike conversions that cross between different quantities.
What is a fathom?
Six feet, the traditional depth unit on marine charts.
What is a rod?
Sixteen and a half feet, or a quarter of a chain; it survives in old deeds and fence estimating.
Why does my answer differ from another converter?
Almost always because the other tool rounded the factor before multiplying. This page keeps full double precision through the calculation and rounds only for display, and it prints the factor it used so you can see where any difference came from.
Is there a quick way to do ftm to rd in my head?
Plenty of people do this in their head: divide by 2.8 instead of using the exact factor 0.3636363636. At 100 that shortcut gives 35.714286 rods, off by 0.6494 rods or about 1.79%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Fathoms to rods reference tables
| Fathoms | Rods |
|---|---|
| 0.5 ftm | 0.181818 rd |
| 1 ftm | 0.363636 rd |
| 2 ftm | 0.727273 rd |
| 3 ftm | 1.09091 rd |
| 5 ftm | 1.81818 rd |
| 10 ftm | 3.63636 rd |
| 20 ftm | 7.27273 rd |
| 25 ftm | 9.09091 rd |
| 50 ftm | 18.1818 rd |
| 75 ftm | 27.2727 rd |
| 100 ftm | 36.3636 rd |
| 250 ftm | 90.9091 rd |
| 500 ftm | 181.818 rd |
| 1000 ftm | 363.636 rd |
| 5000 ftm | 1818.18 rd |
Exact factor: 1 fathom = 0.363636363636 rods.
| Quantity | ftm | rd |
|---|---|---|
| A credit card’s long edge | 0.04681 ftm | 0.01702 rd |
| A door height | 1.111 ftm | 0.404 rd |
| An Olympic pool | 27.34 ftm | 9.942 rd |
| The Eiffel Tower | 180.4 ftm | 65.62 rd |
| A marathon | 2.307e+04 ftm | 8390 rd |
| Earth’s diameter | 6.967e+06 ftm | 2.534e+06 rd |
Published reference values, converted with the same factor this page uses.