How many feet are in 1 chain?

In traditional land surveying, 1 chain = 66 feet (Gunter’s chain). Some engineering uses also define a 100-foot chain. This converter supports both.

How do you convert chains to feet?

Multiply the number of chains by the length of your chain. For the standard surveyor’s chain: feet = chains × 66. For the 100 ft engineer’s chain: feet = chains × 100.

Can I convert feet back to chains?

Yes. Divide the feet by 66 to get surveyor’s chains, or by 100 to get engineer’s chains. This page includes the reverse calculator.

Chains to Feet Converter

Convert chains to feet and feet to chains instantly. Supports the standard 66 ft surveyor’s chain and the 100 ft engineer’s chain. Includes formulas, quick table, and surveying notes.

Quick conversion inputs

Pick the chain that matches your source, then enter chains or feet. Use Calculate for deterministic rounding.

Chains

Feet = chains × chain length

Feet (reverse)

Chains = feet ÷ chain length

Feet from chains

0.0000 ft

Surveyor’s chain (66 ft)

66 ft per chain

Feet from chains 0.0000 ft

Chains from feet 0.0000 ch

How to Use This Converter

Choose the chain length that matches your measurements (66 ft for surveyor’s chain or 100 ft for engineer’s chain). Enter the number of chains you want to convert or the feet you already have, then click Calculate. The results card shows the deterministic conversion using the rounding strategy described below.

Methodology

The calculator uses the fixed chain lengths from surveying and engineering practice. Feet = chains × chain_length, and chains = feet ÷ chain_length. The values are rounded to four decimal places so the numbers remain stable across browsers.

Inputs accept decimal precision for accurate field notes.
Chain length selection ensures the same factor is used for both forward and reverse conversions.
Reset returns the defaults (1 chain = 66 ft) and clears any validation alerts.

Full original guide (expanded)

Surveying, land records, or historical documents — this tool converts chains to feet and feet to chains. Choose the chain type: the classic 66 ft Gunter’s chain or the 100 ft engineer’s chain.

Chains	Feet (66 ft)	Feet (100 ft)	Notes
1	66	100	1 chain
2	132	200	66 ft × 2
5	330	500	≈ 1 furlong (660 ft) = 10 chains
10	660	1000	10 chains = 1 furlong
80	5280	8000	80 chains = 1 mile (survey)

Chains in surveying

The surveying (Gunter’s) chain is defined as 66 feet. This is the value you will see in most land survey documents, older plats, and US public land surveys.

The engineer’s chain is a convenient 100 feet. Some construction or engineering specs may quote chains in this way; that’s why this converter lets you switch between 66 ft and 100 ft.

The equations listed in the Formulas section above reuse these exact chain lengths for every calculation.

FAQ

1. How many chains in a mile?

With 66 ft chains: 1 mile = 5,280 ft → 5,280 ÷ 66 = 80 chains.

2. What is a furlong?

1 furlong = 10 chains = 660 ft (with the 66 ft chain).

3. Which value should I use?

If you are dealing with historical or cadastral records, pick 66 ft. If your spec explicitly says “100 ft chain”, pick 100 ft.

Related length converters

Surveying notes

Always confirm chain standard.
Round to 0.01 chains for field notes.
Keep units consistent in plats.

Formulas

feet = chains × chain_length (survey: 66 ft, engineer: 100 ft)

chains = feet ÷ chain_length (survey: ÷ 66, engineer: ÷ 100)

Inputs and outputs are rounded to four decimal digits for parity across browsers.

Citations

NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures

NIST — SI units — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/owm/metric-si/si-units

Changelog

0.1.0-draft — 2026-01-19: Initial draft (review required).

✓ Verified by Ugo Candido Last Updated: 2026-01-19 Version 0.1.0-draft

Version 1.5.0