Convert Nautical League (UK) (nl (UK)) to Nautical Mile (UK) (NM (UK)) instantly.
About these units
Nautical League (UK) (nl (UK))
This older British unit corresponds to 3 UK nautical miles, or 18,240 feet (about 5,563.6 meters), slightly longer than the international version. Before international standardization, distances in British naval operations were often recorded using UK nautical leagues, especially in long-range maritime planning. Like other historical British units, the UK nautical league reflects the era when each naval power maintained its own measurement standards. While no longer used for navigation, it appears in historic ship logs, naval battles, and exploration records—especially for events predating the 20th century. For historians, the distinction between the UK league and the international one is critical to accurate interpretation of maritime distances.
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.