Length Unit Converter
| Unit | Symbol | = base units |
|---|---|---|
| meter | m | 1 m |
| millimeter | mm | 0.001 m |
| centimeter | cm | 0.01 m |
| kilometer | km | 1,000 m |
| cun (Chinese) | 寸 | 0.033333333 m |
| chi (Chinese) | 尺 | 0.333333333 m |
| li (Chinese) | 里 | 500 m |
| inch | in | 0.0254 m |
| foot | ft | 0.3048 m |
| yard | yd | 0.9144 m |
| mile | mi | 1,609.344 m |
| nautical mile | nmi | 1,852 m |
| zhang (Chinese) | 丈 | 3.333333333 m |
| fathom | ftm | 1.8288 m |
| chain | ch | 20.1168 m |
How to Use
Overview
Length crosses three systems at once: metric metres, centimetres and kilometres; the Chinese market chi, cun, zhang and li; and imperial inches, feet, yards and miles, plus the nautical mile and the fathom and chain used at sea. Built on the metre with fifteen units, the table holds one chi at a third of a metre, one cun at a thirtieth and one li at 500 m, so a tailor order, an English drawing and a sea route can be aligned without multiplying factors by hand. Each unit keeps its defined value, so pipe sizes and screen diagonals convert without a trade rounding creeping in. The chi is the interesting one because it is a decimal fraction of the metre rather than an independent standard: the 1929 reform fixed one chi at one third of a metre and one cun at one thirtieth, which is why a three-chi rod is exactly one metre and a Chinese ruler can be read directly in both systems. Shipping uses a different logic again, since the nautical mile was chosen to match a minute of latitude, and a chain of 66 feet survives because surveyors once carried a hundred-link chain of that length. A chain is still handy because it divides evenly into both feet and miles.
Features
- Fifteen units: metre, millimetre, centimetre, kilometre, cun, chi, li, inch, foot, yard, mile, nautical mile, zhang, fathom, chain
- Market units follow the national standard: one chi is 1/3 m, one cun is 1/30 m, one li is 500 m
- Zhang, chi and cun form a chain: one zhang is ten chi, or 3.3333 m, for cloth and legacy drawings
- The imperial chain is complete: 12 in to a foot, 3 ft to a yard, 1,760 yd to a mile
- Maritime units: nautical mile at 1,852 m, fathom at 1.8288 m for soundings, chain at 20.1168 m
- Expression input, zero to eight decimals, batch conversion and TXT or CSV export
How to use
- Enter a length or expression, for example 1.75 or 3*12
- Choose the source unit: chi for tailoring, inches for drawings, nautical miles for routes
- Leave the target empty for all fifteen results, or pin one such as metre or kilometre
- Press Swap to convert the result back and cross-check two figures on the same slip
- Paste several lines and export CSV for a material list or a mileage log
Notes
- Fifteen length units run from metre, millimetre and kilometre through cun, chi, li and zhang to inch, foot, yard, mile, nautical mile, fathom and chain, with the metre as the base.
- Market units follow one third of a metre per chi, one thirtieth per cun, ten chi per zhang and 500 m per li, so tailoring and carpentry need them aligned with survey metres first.
- The nautical mile is 1,852 m, a fathom 1.8288 m and a chain 20.1168 m; chart soundings use fathoms while distances use nautical miles, and neither substitutes for the other.
- A mile is 1,609.344 m, a yard 0.9144 m and a foot 0.3048 m, so imperial units are whole multiples internally and only metric conversion produces decimals.
- The Taiwan chi at about 0.3036 m and historical li-paces are not covered; CSV exports numbers, so add a unit column when the sheet needs one.
- The yard is three feet, 0.9144 m, still quoted in golf and cloth trading
- The mile is 1,760 yards, 1,609.344 m, about sixty percent longer than a kilometre
- The international nautical mile is exactly 1,852 m, close to one minute of latitude, used for sea and air