To convert chains to inches, multiply by 792. That factor is the whole relationship: both units measure length, so the conversion is a proportion with no offset and no substance-specific constant.
Sixty-six feet — the length of a cricket pitch, and the unit the US Public Land Survey was laid out in. Exactly 25.4 millimetres since the 1959 international yard agreement.
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". Two tables follow: rounded steps for quick lookup, and a set of real reference quantities converted into inches, which is usually more useful than the bare number.
The formula
chains- The amount you are converting, in chains
792- The exact number of inches in one chain
inches- The converted result
How it works, step by step
- Enter the value in chains.
- It is multiplied by 792, the exact factor between the two units.
- The answer is shown in inches, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
A door height: 0.101 ch in inches
Take a door height, roughly 0.101 ch. The conversion is a single multiplication — 0.101 × 792 — giving 79.992 in. Because the relationship is proportional, doubling the input doubles the answer to 159.984 in.
An Olympic pool: 2.49 ch in inches
An Olympic pool comes to about 2.49 ch. Multiplying by the factor: 2.49 × 792 = 1972.08 in. Dividing the answer back by 792 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 inches are in one chain?
Exactly 792. 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 chains to inches?
inches = chains × 792. Reversed, chains = inches ÷ 792, which is the same as multiplying by 0.00126262626263.
Which is the bigger unit, the chain or the inch?
The chain. One chain equals 792 inches.
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 chain?
Sixty-six feet — the length of a cricket pitch, and the unit the US Public Land Survey was laid out in.
What is a inch?
Exactly 25.4 millimetres since the 1959 international yard agreement.
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 ch to in in my head?
Plenty of people do this in their head: multiply by 800 instead of using the exact factor 792. At 100 that shortcut gives 80,000 inches, off by 800 inches or about 1.01%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Chains to inches reference tables
| Chains | Inches |
|---|---|
| 0.5 ch | 396 in |
| 1 ch | 792 in |
| 2 ch | 1584 in |
| 3 ch | 2376 in |
| 5 ch | 3960 in |
| 10 ch | 7920 in |
| 20 ch | 15,840 in |
| 25 ch | 19,800 in |
| 50 ch | 39,600 in |
| 75 ch | 59,400 in |
| 100 ch | 79,200 in |
| 250 ch | 198,000 in |
| 500 ch | 396,000 in |
| 1000 ch | 792,000 in |
| 5000 ch | 3.96e+06 in |
Exact factor: 1 chain = 792 inches.
| Quantity | ch | in |
|---|---|---|
| A credit card’s long edge | 0.004255 ch | 3.37 in |
| A door height | 0.101 ch | 80 in |
| An Olympic pool | 2.485 ch | 1969 in |
| The Eiffel Tower | 16.4 ch | 1.299e+04 in |
| A marathon | 2098 ch | 1.661e+06 in |
| Earth’s diameter | 6.334e+05 ch | 5.017e+08 in |
Published reference values, converted with the same factor this page uses.