In genetics, a centimorgan (abbreviated cM) is a unit for measuring genetic linkage. It is defined as the distance between chromosome positions for which the expected average number of intervening chromosomal crossovers in a single generation is 0.01. It is often used to infer distance along a chromosome. However, It is not a true physical distance.

Centymorgany, w skrócie cM – to jednostka miary stosowana w genetyce do wyrażenia odległości pomiędzy genami położonymi na tym samym chromosomie.