2 Chr 27:1

27:1 Jotham . . . sixteen years. Reigned 750–732 b.c. Jotham reigned during the period of his father Uzziah’s leprosy (750–740 b.c.), and had co-regency with his son Ahaz (735–732 b.c.). For six years he was the sole monarch. The figure “sixteen years” here and in v. 8 probably refers to his co-regency with his father and his independent reign. Adding his four years with Ahaz brings the total to twenty years (2 Kin. 15:30).