Convert Chain to US Survey Foot
Convert chains to us survey feet instantly. 1 chain = 65.999868 us survey foot — use the live calculator, the exact formula, a conversion table and worked examples. Also check the US Survey Foot to Chain converter for the reverse conversion.
Units explained
Chain
A chain is an Imperial unit of length equal to 66 feet (20.1168 m), or exactly 4 rods or 100 links. It is the central unit in the Gunter chain-based land-survey system.
Defined by Edmund Gunter in 1620 specifically to make land-area arithmetic easy: 10 square chains = 1 acre exactly. The 66-foot length and 100-link subdivision were chosen so chain measurements could be added decimally.
Chains are the fundamental unit of legacy US public land surveys (the entire US township-and-range system uses chains). Modern survey work generally uses meters or feet, but legacy deeds remain in chains.
Invented by Edmund Gunter in 1620; standardised throughout English and American land survey; became exact via the 1959 International Yard and Pound Agreement.
US Survey Foot
The US Survey Foot is a legacy unit of length defined as exactly 1200/3937 meters (approximately 0.3048006 m). It differs from the modern international foot by about 2 parts per million.
Established in the United States by the Mendenhall Order of 1893, which defined the foot in terms of the meter as 1200/3937 m. The US continued using this value for surveying even after the 1959 International Yard and Pound Agreement standardized the international foot at exactly 0.3048 m.
Used in US land surveying, geodetic measurements, state plane coordinate systems, and legal land descriptions. The US Survey Foot was officially deprecated by NIST and NOAA effective December 31, 2022, with the international foot becoming the sole US standard. Legacy data and recorded land surveys still reference it.
Mendenhall Order of 1893 defined the foot as 1200/3937 m; persisted in US surveying after 1959; officially deprecated by NIST/NOAA as of December 31, 2022.
Chain to US Survey Foot conversion formula
Note: this conversion uses a generally accepted modern value. Historical and regional definitions of this unit varied across times and places.
The relationship between chains and us survey feet:
To convert chains to us survey feet, multiply the value in chains by 65.999868. To reverse, multiply us survey feet by 0.0151515455.
How to use this converter
Type a value into the calculator. The result in us survey feet updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the US Survey Foot to Chain converter for the reverse direction.
Step-by-step: convert chains to us survey feet
- Write down the value in chains (ch).
- Multiply that value by the factor 65.999868.
- The product is the equivalent value in us survey feet (sft).
- To reverse, multiply the us survey foot value by 0.0151515455.
Worked examples
Example 1 — Convert 1 ch to sft:
1 × 65.999868 = 65.999868 sft
Example 2 — Convert 100 ch to sft:
100 × 65.999868 = 6599.9868 sft
Chain to US Survey Foot conversion table
Standard reference values for converting chains to us survey feet:
| Chain [ch] | US Survey Foot [sft] |
|---|---|
| 0.01 | 0.65999868 |
| 0.1 | 6.5999868 |
| 1 | 65.999868 |
| 2 | 131.999736 |
| 3 | 197.999604 |
| 4 | 263.999472 |
| 5 | 329.99934 |
| 10 | 659.99868 |
| 20 | 1319.99736 |
| 30 | 1979.99604 |
| 40 | 2639.99472 |
| 50 | 3299.9934 |
| 100 | 6599.9868 |
| 500 | 32999.934 |
| 1000 | 65999.868 |
Frequently asked questions
How many us survey feet is 1 chain?
How do I convert chains to us survey feet?
How do I convert us survey feet back to chains?
How many us survey feet is 100 chains?
Popular length unit conversions
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Metric / SI (4 units)
Imperial / US Customary (26 units)
Sources & references
Conversion factor (1 ch = 65.999868 sft) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.