To convert nautical miles to chains, multiply by 92.06235584. That factor is the whole relationship: both units measure length, so the conversion is a proportion with no offset and no substance-specific constant.
Exactly 1,852 metres — one minute of latitude, the basis of marine and air navigation. Sixty-six feet — the length of a cricket pitch, and the unit the US Public Land Survey was laid out in.
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". The tables underneath give both a plain step-by-step lookup and a list of real quantities expressed in chains, so you can sanity-check whether your answer is a plausible size.
The formula
nautical miles- The amount you are converting, in nautical miles
92.0623558419- The exact number of chains in one nautical mile
chains- The converted result
How it works, step by step
- Enter the value in nautical miles.
- It is multiplied by 92.0623558419, the exact factor between the two units.
- The answer is shown in chains, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
Earth’s diameter: 6880 nmi in chains
At 6880 nmi (earth’s diameter), the same quantity in chains is 6880 × 92.0624 = 633,389 ch. One nautical mile is 92.0624 chains, so the numbers grow as expected.
An Olympic pool: 0.027 nmi in chains
Take an olympic pool, roughly 0.027 nmi. The conversion is a single multiplication — 0.027 × 92.0624 — giving 2.48568 ch. Because the relationship is proportional, doubling the input doubles the answer to 4.97137 ch.
How to read your score
Frequently asked questions
How many chains are in one nautical mile?
Exactly 92.0623558419. 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 nautical miles to chains?
chains = nautical miles × 92.0623558419. Reversed, nautical miles = chains ÷ 92.0623558419, which is the same as multiplying by 0.0108622030238.
Which is the bigger unit, the nautical mile or the chain?
The nautical mile. One nautical mile equals 92.0624 chains.
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 nautical mile?
Exactly 1,852 metres — one minute of latitude, the basis of marine and air navigation.
What is a chain?
Sixty-six feet — the length of a cricket pitch, and the unit the US Public Land Survey was laid out in.
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 nmi to ch in my head?
Plenty of people do this in their head: multiply by 90 instead of using the exact factor 92.06235584. At 100 that shortcut gives 9000 chains, off by 206.2 chains or about 2.24%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Nautical Miles to chains reference tables
| Nautical Miles | Chains |
|---|---|
| 0.5 nmi | 46.0312 ch |
| 1 nmi | 92.0624 ch |
| 2 nmi | 184.125 ch |
| 3 nmi | 276.187 ch |
| 5 nmi | 460.312 ch |
| 10 nmi | 920.624 ch |
| 20 nmi | 1841.25 ch |
| 25 nmi | 2301.56 ch |
| 50 nmi | 4603.12 ch |
| 75 nmi | 6904.68 ch |
| 100 nmi | 9206.24 ch |
| 250 nmi | 23,015.6 ch |
| 500 nmi | 46,031.2 ch |
| 1000 nmi | 92,062.4 ch |
| 5000 nmi | 460,312 ch |
Exact factor: 1 nautical mile = 92.0623558419 chains.
| Quantity | nmi | ch |
|---|---|---|
| A credit card’s long edge | 4.622e-05 nmi | 0.004255 ch |
| A door height | 0.001097 nmi | 0.101 ch |
| An Olympic pool | 0.027 nmi | 2.485 ch |
| The Eiffel Tower | 0.1782 nmi | 16.4 ch |
| A marathon | 22.78 nmi | 2098 ch |
| Earth’s diameter | 6880 nmi | 6.334e+05 ch |
Published reference values, converted with the same factor this page uses.