Where can it be found in the bible that how many years king david rule as a king?

Answer 1

(2 Samuel 5:4, 5) 4 Thirty years old was David when he became king. For forty years he ruled as king. 5 In He′bron he ruled as king over Judah for seven years and six months; and in Jerusalem he ruled as king for thirty-three years over all Israel and Judah.