A cable length or length of cable is a nautical unit of measure equal to one tenth of a nautical mile or approximately 100 fathoms.

Owing to anachronisms and varying techniques of measurement, a cable length can be anywhere from 169 to 220 metres (185 to 241 yd), depending on the standard used.

As rope is "closed" (the final stage in manufacture) the length reduces, thus the ropewalk at Chatham Dockyard is 1⁄4 mile (0.40 km) long in order to produce standard 220 metres (120 fathoms) coils.

In 2008 the Royal Navy in a handbook defined it as A cable equals one-tenth of a sea mile - 608 ft.

The length of a ship's hempen anchor cable was formerly 101 fathoms.