Khabib Nurmagomedov’s father, Abdulmanap Nurmagomedov, was born in 1962, and Khabib was born on September 20, 1988, so he was about 25 or 26 when Khabib was born.

Quick note

The exact age depends on Abdulmanap’s birthday in 1962, but the usual way of stating it is 26 years old.

TL;DR

Abdulmanap Nurmagomedov was roughly 26 when Khabib was born.