Chains (ch)
0
Equivalent length
Accurate length conversion between metres, chains, yards, feet, furlongs, and miles
Convert metres to chains instantly with precise calculations. Includes bidirectional conversion and a complete imperial length breakdown for surveying, mapping, and land measurement in 2026.
Professional length conversion for surveying, railways, mapping, and historical records
The surveyor’s chain is defined as exactly 20.1168 metres, derived from 66 feet with each international foot equal to 0.3048 metres. This gives a simple, exact factor: 1 chain = 20.1168 m and 1 m ≈ 0.0497097 chains. All conversions on this page use this fixed relationship, so every result is mathematically precise for 2026.
Switch easily between metres to chains and chains to metres. See the equivalent values at the same time in yards, feet, furlongs, and miles, so you can interpret old survey plans, railway diagrams, and land registry documents while thinking in modern metric units.
Ideal for land surveyors, civil engineers, GIS specialists, historians, and students working with British or Commonwealth mapping systems. Chains remain embedded in older cadastral plans, railway distances, and agricultural layouts, so reliable conversion to metres is critical for modern design and analysis.
Select conversion direction and enter your value below
The surveyor’s chain (Gunter’s chain) is an imperial unit of length equal to 66 feet, or 22 yards. With the international foot defined as exactly 0.3048 metres, one chain corresponds to exactly 20.1168 metres. This makes the conversion straightforward: to go from metres to chains you divide by 20.1168, and to go from chains to metres you multiply by 20.1168.
Chains were designed to make land area calculations simple: an acre is 10 square chains, and a furlong equals 10 chains, so many traditional field dimensions and railway distances are multiples of a chain. Modern surveying equipment works in metres and kilometres, but older maps, deeds, and engineering drawings often use chains, so a reliable converter bridges the gap between historical and modern units.
Because all of these relationships are defined exactly, the conversion between chains and metres is precise and consistent across surveying, railways, and land records.
100 m ÷ 20.1168 ≈ 4.97 chains
A distance of 100 metres is just under 5 chains. That same length is about 5.47 furlongs per kilometre section of a railway (since 1 km ≈ 49.7 chains), so chains provide a convenient countable unit along long straight routes.
Ten chains make a furlong and eighty chains make a mile, so chains fit naturally into the classic furlong–mile framework used in older British surveying and transport systems.
This table shows useful metre values converted into chains, with their equivalent yards and miles. It is especially helpful when translating between metric engineering drawings and older chain-based land surveying records.
| Metres (m) | Chains (ch) | Yards (yd) | Miles (mi) | Common Reference |
|---|---|---|---|---|
| 20.1168 m | 1.000 ch | 22 yd | 0.0125 mi | One surveyor’s chain |
| 50 m | 2.486 ch | 54.7 yd | 0.0311 mi | Short field edge |
| 100 m | 4.971 ch | 109.4 yd | 0.0621 mi | Straight road section |
| 201.168 m | 10.000 ch | 220 yd | 0.1250 mi | One furlong |
| 400 m | 19.90 ch | 437 yd | 0.2485 mi | One lap of track (approx.) |
| 804.672 m ★ | 40.000 ch | 880 yd | 0.500 mi | Half mile |
| 1,000 m | 49.71 ch | 1,094 yd | 0.6214 mi | One kilometre |
| 1,609.344 m | 80.000 ch | 1,760 yd | 1.000 mi | One mile |
| 2,000 m | 99.42 ch | 2,187 yd | 1.2427 mi | Approx. 2 km |
| 5,000 m | 248.55 ch | 5,468 yd | 3.1069 mi | 5 km road race |
| 10,000 m | 497.10 ch | 10,936 yd | 6.2137 mi | 10 km road race |
A chain is a traditional surveying unit equal to 66 feet or 22 yards. It was introduced by Edmund Gunter in the 17th century to simplify land area calculations. Because 10 square chains equal an acre, surveyors could compute field areas quickly using integer values without complex arithmetic.
In Britain and some Commonwealth countries, railway distances were historically recorded in miles and chains. A location might be described as “10 miles 40 chains” from a reference point. While modern systems increasingly use kilometres, legacy documentation and infrastructure markings still reference chains.
Many cadastral maps, title deeds, and agricultural plans produced in the 19th and 20th centuries specify field lengths and boundaries in chains. Converting these older measurements into metres is essential when integrating historical data into modern GIS systems or redesigning existing parcels.
Although new surveys typically use metres, chains remain important whenever you interpret older documents or compare modern layouts with historical records. Knowing that 1 chain equals 20.1168 metres allows easy translation between the two worlds without losing precision.
Any m → ch: Divide by 20.1168 | e.g., 100 m ÷ 20.1168 ≈ 4.97 ch
Any ch → m: Multiply by 20.1168 | e.g., 10 ch × 20.1168 = 201.168 m
1 furlong: 10 ch | 1 mile: 80 ch | 1 chain: 22 yd = 66 ft
Because chains are much longer than metres, confusing the units can introduce large errors in land area or railway distance. For example, 5 chains is over 100 metres, not 5 metres. Always check whether an old plan uses metres, yards, or chains before digitising or redesigning it.
Explore how inches, feet, yards, chains, furlongs, and miles interrelate in traditional surveying systems, and how they connect to the metric system via exact definitions.
Surveying Guides →Access a full suite of converters for length, area, volume, mass, pressure, and more, designed for both technical and everyday users working across metric and imperial systems.
Browse Converters →Learn best practices for integrating historical chain-based maps into modern GIS workflows using consistent and exact conversion factors.
GIS Resources →