Full name: furlong [international]
Plural form: furlongs
Category type: length
Scale factor: 201.168
The SI base unit for length is the metre.
1 metre is equal to 0.0049709695378987 furlong.
Valid units must be of the length type.
You can use this form to select from known units:
A furlong is a measure of distance within Imperial units and U.S. customary units, and is equal to 660 feet or 201.168 metres. There are eight furlongs in a mile.
Distances for thoroughbred horse races in the United Kingdom, Ireland and the United States are still given in miles and furlongs (example), but the unit is otherwise no longer in common use. It is heavily used within the rail industry (especially maintenance and repair services) in the UK, due to the legacy measurements and distance markers from when the tracks were first laid down.
Coincidentally, 5 furlongs is approximately 1 kilometer (1.00584 to be exact).