How old was Mary when she had Jesus?

What the Gospels say, and don’t

No Gospel gives Mary’s age, or Joseph’s. Luke gives her situation instead.

Now in the sixth month, the angel Gabriel was sent from God to a city of Galilee named Nazareth, to a virgin pledged to be married to a man whose name was Joseph, of David’s house. The virgin’s name was Mary.

“Pledged to be married” is a stage modern weddings don’t have. A Jewish betrothal was a binding contract: the couple were already legally husband and wife, and ending it took a divorce, which is exactly what Joseph first plans (Matthew 1:19). But the bride went on living in her father’s house until the wedding. Matthew says Mary was found pregnant “before they came together” (Matthew 1:18), and Luke still calls her “pledged to be married” on the road to Bethlehem (Luke 2:5).

How young were brides then?

Girls in Mary’s world were often betrothed at twelve or thirteen, by arrangement between their families. The written rules come from a little later, but they show the custom. The Mishnah, the Jewish law code compiled around AD 200, treats a girl’s vows as binding from twelve years and a day (Niddah 5:6), and gives a betrothed virgin twelve months to prepare for the wedding once the husband asks for it (Ketubot 5:2). Roman law set twelve as the youngest legal age of marriage for a girl (Digest 23.2.4).

Put together, the usual estimate is a girl in her early or middle teens at the birth of her first child. That is an inference from custom, not a fact about Mary. Some girls married later, and the Gospels give no hint either way.

Where “sixteen” comes from

The only ancient text that gives a number is the Protoevangelium of James, written around AD 150 and never part of any Bible. It has Mary raised in the Temple from the age of three and handed to Joseph’s care when she turns twelve, and it says she was sixteen when the angel’s promise came true and she conceived. The same book first names her parents, Joachim and Anne, and makes Joseph an old widower with grown sons.

Much of later tradition grew from it, including the feast of the Presentation of Mary on November 21, kept by Catholics and Orthodox. Historians read the book as devotion written a century after the events, not as family memory, so its sixteen is a guess as old as the second century.

Young, and not passive

Whatever her age, Luke does not draw a frightened child. Mary questions the angel before she agrees.

Mary said to the angel, “How can this be, seeing I am a virgin?”

Then she gives her answer, hurries into the hill country of Judah to see her relative Elizabeth, pregnant “in her old age” (Luke 1:36), and sings the Magnificat. Within months she is walking to Bethlehem, heavily pregnant. Luke sets the two women side by side: one who had stopped hoping, one whose life had barely begun.

Mary appears again at the foot of the cross (John 19:25) and among the first believers in Jerusalem, praying with the apostles (Acts 1:14). If she was about fifteen when Jesus was born, she was around fifty when he died.