To convert picas to chains, multiply by 0.0002104377104. 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. Twelve points, or 1/6 inch — the column-width unit of print layout.
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
picas- The amount you are converting, in picas
0.000210437710438- The exact number of chains in one pica
chains- The converted result
How it works, step by step
- Enter the value in picas.
- It is multiplied by 0.000210437710438, 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
A marathon: 9.97e+06 pica in chains
Take a marathon, roughly 9.97e+06 pica. The conversion is a single multiplication — 9.97e+06 × 0.000210438 — giving 2098.06 ch. Because the relationship is proportional, doubling the input doubles the answer to 4196.13 ch.
The Eiffel Tower: 7.8e+04 pica in chains
Take the eiffel tower, roughly 7.8e+04 pica. The conversion is a single multiplication — 7.8e+04 × 0.000210438 — giving 16.4141 ch. Because the relationship is proportional, doubling the input doubles the answer to 32.8283 ch.
How to read your score
Frequently asked questions
How many chains are in one pica?
Exactly 0.000210437710438. 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 picas to chains?
chains = picas × 0.000210437710438. Reversed, picas = chains ÷ 0.000210437710438, which is the same as multiplying by 4752.
Which is the bigger unit, the pica or the chain?
The chain. One pica is only 0.000210438 of a chain, so it takes 4752 picas to make one chain.
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 pica?
Twelve points, or 1/6 inch — the column-width unit of print layout.
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 pica to ch in my head?
Plenty of people do this in their head: divide by 4800 instead of using the exact factor 0.0002104377104. At 100 that shortcut gives 0.020833333 chains, off by 0.0002104 chains or about 1.00%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Picas to chains reference tables
| Picas | Chains |
|---|---|
| 0.5 pica | 0.000105219 ch |
| 1 pica | 0.000210438 ch |
| 2 pica | 0.000420875 ch |
| 3 pica | 0.000631313 ch |
| 5 pica | 0.00105219 ch |
| 10 pica | 0.00210438 ch |
| 20 pica | 0.00420875 ch |
| 25 pica | 0.00526094 ch |
| 50 pica | 0.0105219 ch |
| 75 pica | 0.0157828 ch |
| 100 pica | 0.0210438 ch |
| 250 pica | 0.0526094 ch |
| 500 pica | 0.105219 ch |
| 1000 pica | 0.210438 ch |
| 5000 pica | 1.05219 ch |
Exact factor: 1 pica = 0.000210437710438 chains.
| Quantity | pica | ch |
|---|---|---|
| A credit card’s long edge | 20.22 pica | 0.004255 ch |
| A door height | 480 pica | 0.101 ch |
| An Olympic pool | 1.181e+04 pica | 2.485 ch |
| The Eiffel Tower | 7.795e+04 pica | 16.4 ch |
| A marathon | 9.967e+06 pica | 2098 ch |
| Earth’s diameter | 3.01e+09 pica | 6.334e+05 ch |
Published reference values, converted with the same factor this page uses.