Convert Furlong (US Survey) (fur (US)) to Nautical Mile (UK) (NM (UK)) instantly.
About these units
Furlong (US Survey) (fur (US))
The US Survey Furlong is defined as 660 US Survey Feet (~201.168 meters), exactly 10 US survey chains. It was historically used in land measurement, agriculture, and railroads. Furlongs remain relevant for interpreting historical property layouts and land grants, particularly in rural and agricultural contexts. The unit's convenience derives from its direct relationship with the acre and chain, facilitating rapid calculation of large land areas. While the furlong is largely obsolete in modern measurement, it persists in legal and historical survey references, bridging imperial traditions and contemporary land-use documentation.
Nautical Mile (UK) (NM (UK))
The UK nautical mile was historically defined as 6,080 feet, slightly longer than the international nautical mile (1,852 meters). Before international standardization in 1929, British charts and maritime documents relied on this definition. It approximated one minute of latitude but used British feet rather than an exact metric conversion. Although the UK adopted the international nautical mile long ago, many older navigation charts, historical records, and maritime traditions still reference the UK version. Researchers dealing with archival naval documents must carefully distinguish between the two definitions to avoid errors in distance or speed calculations. The UK nautical mile is a reminder of the era before global standardization when each nation maintained its own measurement conventions—even for activities as universally critical as seafaring.