2 Kings 11:21

Jehoash [was] {seven years old} when he began to reign.

2 Chronicles 24:1-14

Joash [was] seven years old when he became king, and he reigned forty years in Jerusalem. And the name of his mother [was] Zibiah from Beersheba.

2 Kings 11:4

But in the seventh year Jehoiada sent and took the commanders of the hundreds of the Carites and the runners, and he brought them to himself to the temple of Yahweh. Then he {made} a covenant with them and made them swear in the house of Yahweh and showed them the son of the king.

2 Kings 22:1

Josiah was eight years old when he began to reign, and he reigned thirty-one years in Jerusalem. The name of his mother [was] Jedidah the daughter of Adaiah from Bozkath.

Treasury of Scripture Knowledge

Summary

Seven years old was Jehoash when he began to reign.

Bible References

General references

2 Kings 11:4
But in the seventh year Jehoiada sent and took the commanders of the hundreds of the Carites and the runners, and he brought them to himself to the temple of Yahweh. Then he {made} a covenant with them and made them swear in the house of Yahweh and showed them the son of the king.
2 Kings 22:1
Josiah was eight years old when he began to reign, and he reigned thirty-one years in Jerusalem. The name of his mother [was] Jedidah the daughter of Adaiah from Bozkath.
2 Chronicles 24:1
Joash [was] seven years old when he became king, and he reigned forty years in Jerusalem. And the name of his mother [was] Zibiah from Beersheba.