Furlong

A furlong is a measurement of length equal to 201.168 meters, 220 yards, or 660 feet. Below are relationships between furlongs and other common measurements of length:

What is a furlong

A furlong is a unit of length in the US customary and imperial systems of measurement.

Furlong definition

In 1959, the definition of the furlong was standardized based on the international yard to be equal to exactly 220 yards, which is equivalent to 201.168 m. Like many other units of measurement, the definition of the furlong changed throughout history, but the international definition only varies very slightly from the definitions previously used in the UK and the US. For example, the previous US definition was based on the US survey foot, making a furlong equal to 201.1684 m.

History of the furlong

The furlong originated as an old English measurement of length based on the average distance that a team of oxen could plough without having to rest. A furrow is a long narrow trench made with a plow for the purpose of planting seeds or for irrigation. Its name is derived from the Old English word "furlang." Furh means furrow (long narrow trench made with a plow) while lang means length. Thus, a furlong is a measure that describes the length of a typical furrow at the time it was developed, which dates back to at least the 9th century. This distance was standardized to equal exactly 40 rods or 10 chains.

The definition of the furlong and rod eventually changed with the redefinition of feet and yards in the 1959 international agreement. The rod changed from 15 old feet to 16.5 new feet, the furlong changed from 600 old feet to 660 new feet, and the acre changed from 36,000 old square feet to 43,560 new square feet.

Furlong usage

The furlong is rarely used today outside of horse racing. It is still used in horse racing largely due to tradition, since it was the accepted unit of measure at the birth of horse racing in 16th century England. It is equal to one-eighth of a mile, and though some horse racing tracks use yards as the primary measure of distance, many still use the furlong. It is also sometimes used in agriculture to measure field length and distances, or for surveying purposes in the US. Otherwise, it is a little known, rarely used measurement of distance that has been replaced by many others.

Definitions of the furlong

The definition of the furlong differs slightly depending on whether it is defined based on the international yard or the US survey foot. The international yard is defined as 0.9144 meters. The US does not formally define survey yards, but based on the survey foot, which is equal to 0.30480061 meters, the "survey yard" is 0.91440183 yards.

Practically, the difference in measurement in the furlong based on the difference between the international yard and survey foot is too small to result in significant consequences. Since survey measurements typically involve very large areas with variable conditions anyway, the best reported survey data is expected to have some degree of inaccuracy that would not really be distinguishable from any inaccuracy resulting from the minor difference in definitions of the furlong.

Since the furlong is no longer widely used, it can be useful to be able to convert from furlongs to more widely used units of measurement.

Examples

Convert 72 furlongs to feet and meters.

1. 72 × 660 = 47,520 feet


2. 72 × 201.168 = 14,484.096 meters


3. 72 × 201.1684026 = 14,484.125 meters

There is a 0.029 m difference based on the international yard definition definition (2) and the survey foot definition (3) of the furlong.

Below are some other common furlong conversions.

How many feet in a furlong

There are 660 feet in 1 furlong.

How many yards in a furlong

There are 220 yards in 1 furlong.

How many miles in a furlong

There are 0.125 miles in 1 furlong.

How many meters in a furlong

There are 201.168 meters in 1 furlong.

How many kilometers in a furlong

There are 0.201168 kilometers in 1 furlong.

Did you know?

The furlong is no longer commonly used, except in horse racing in English-speaking countries. Its use in horse racing is mostly due to tradition; when horse racing was first formalized in the 1500s, the furlong was the unit of choice, and this has not changed in most English-speaking countries where horse races are held.

The Kentucky Derby, the world's most famous horse race, is held on the first Saturday of May each year at the Churchill Downs in Louisville. It is a 10-furlong race (1 miles) for 3-year-old horses.