1 nanometer (1 nm) is equal to

The unit of length refers to the internationally recognized standard unit of length. The most commonly used system is the unit SI system. In this system, the unit of length is metre (m). There is another system used for the unit called M.K.S. Unit system. The M.K.S. system is in centimeters (cm) in length. The units of meters and centimeters are related as follows.

$1m=100cm or 1cm={10}^{-2}m$

To measure lengths shorter than cm, there are other units defined. Since m is in SI units, all of these lengths are written in terms of m as follows. Related to millimeters. 

Micrometer $1mm = {10}^{-3}m$

Micrometre $1\mu m={10}^{-6}m$

Nanometer:$1nm={10}^{-9}m$

 Picometer: $1pm={10}^{-12}m$

Femtometre:$1fm={10}^{-15}m$