A Gunter's chain, commonly referred to as a surveyor's chain, is a historical instrument used for measuring land. It was designed by the English mathematician Edmund Gunter in the early 17th century. The chain is 66 feet long, consisting of 100 links, each link being 7.92 inches. The entire length of a Gunter's chain is deliberately chosen to be 66 feet because this makes one tenth of a furlong, and ten chains equal one furlong or 1,320 feet. Additionally, there are 80 chains in one mile.

The use of the Gunter's chain was particularly popular in surveying lands in English-speaking countries, especially in the pre-metric system era. It was instrumental in the creation of standardized acreage measurements used for mapping and planning land. Each chain is typically made of metal, with each link joined by three rings to provide flexibility and durability. This tool was critical in the cadastral surveying and was widely used until more modern measuring equipment replaced it.