How old was King Solomon when he died?
We know how long Solomon reigned.
1 Kings 11:42 And the period that Solomon reigned in Jerusalem over all Israel was forty years.
But we are not told how old he was when he came toi the throne. His son Rehoboam was 41 when Solomon died (1 kings 14:21). His father David reigned 7 years in Hebron and 33 years in Jerusalem. (1 Kings 2:11). He became involved with Solomon's mother Bathsheba some time after he began reigning in Jerusalem.
Solomon was not her first child. If we allow perhaps 10 to 15 years of David's 33 before Solomon's birth, that would make him aged between 18 and 23 when he came to the throne meaning that he died aged around 60.