About this tool
The Length & Distance Converter turns a single value into every common metric, imperial and nautical length unit at once. Type a number, pick the unit you are starting from, and the results grid instantly shows the same distance in millimetres, centimetres, metres, kilometres, inches, feet, yards, miles and nautical miles — plus microns, mils, furlongs, ångströms, light-years and astronomical units for scientific work.
Conversion uses an exact linear factor table with the metre as the base unit. Each unit stores how many of it fit in one metre (mm = 1000, in = 1/0.0254, ft = 1/0.3048, mi = 1/1609.344, nmi = 1/1852, and so on), all derived from the internationally exact definitions 1 inch = 0.0254 m and 1 mile = 1609.344 m. The tool converts your value to metres (value ÷ factor of the source unit) and then multiplies by each target factor, so results never drift from repeated rounding.
Everything runs entirely in your browser with plain JavaScript — nothing is uploaded and there is no network call. Very small or very large results (like light-years) are shown in scientific notation, while everyday values are rounded to six decimals for readability. The source unit is outlined in the grid so you can always see your starting point.