Survey Length Converter
Survey chains, links, rods, and furlongs converted with exact factors.
What it does
American land records still speak Gunter: chains of 66 feet, links, rods, and furlongs that stack neatly into miles and acres. Modern work uses the exact 0.3048 m foot while old deeds may cite the survey foot, 2 parts per million longer.
The tool above converts across links, chains, rods, furlongs, miles, feet, and meters. Pick both ends and every equivalent lists below.
The default 20 chains reads 0.25 miles (1,320 ft, 402.336 m). One mile back-converts to 80 chains, and 10 chains give 660 ft.
Factors follow NIST conversion tables with the Federal Register foot deprecation behind them. Both fix the chain at 66 ft and the acre at 43,560 sq ft used here.
How to use
- Enter the length value.
- Pick the source survey unit.
- Pick the target unit.
- Read the converted line first.
- Scan all units below it.
- Check the table for acre ties.
Formula
- value
- Input length number.
- from
- Foot factor of the source unit.
- to
- Foot factor of the target unit.
- 0.3048
- Exact meters per current foot.
Factors use the current exact foot (0.3048 m) per the 2022 federal switch. Legacy US survey foot values run 2 ppm longer and appear in the table for deed work. Areas square the factors; acreage stays 43,560 sq ft.
Worked example
Example: 20 chains
Defaults: 20 chains to miles.
- Value: 20 chains.
- To feet: 20 x 66 = 1,320 ft.
- To miles: 1,320 / 5,280 = 0.25 mi.
- Check: 80 chains make a mile, 20 / 80 = 0.25.
- Metric: 20 x 20.1168 = 402.336 m.
- Tool shows 0.25 mi with every unit below.
Reference table
| Unit | Feet | Metric |
|---|---|---|
| Link | 0.66 ft | 0.201168 m |
| Chain | 66 ft | 20.1168 m |
| Rod (pole) | 16.5 ft | 5.0292 m |
| Furlong | 660 ft | 201.168 m |
| Mile | 5,280 ft | 1,609.344 m |
| Acre | 43,560 sq ft | 4,046.856 m2 |
Limits
- Linear units; acre needs area math.
- Deed foot type must be labeled.
- Rounding hides sub-link shifts.
- State plane needs surveyor care.
Common mistakes
- Mixing survey and exact feet.
- Reading rods as yards.
- Forgetting 80 chains per mile.
- Squaring linear factors wrongly.
- Trusting rounded deed calls.
Try it yourself
Quick checks. Answers sit tucked under each question.
1 mile to chains?
5,280 / 66 = 80 chains.
10 chains to feet?
10 x 66 = 660 ft.
100 links to rods?
100 x 0.66 / 16.5 = 4 rods.
Questions
How long is a chain?
66 ft, 100 links, 4 rods: 20.1168 m. Ten square chains make an acre.
How long is a link?
7.92 in, 0.66 ft, one hundredth of a chain.
How long is a rod?
16.5 ft, also called pole or perch: a quarter chain.
How long is a furlong?
660 ft, 10 chains, 40 rods: 201.168 m.
Which foot applies?
The 0.3048 m foot for all new work. Legacy deeds may use the US survey foot, 2 ppm longer.
Do old deeds convert cleanly?
Label the foot type on legacy deeds. At 0.1 link precision both feet agree.