How old do you have to be to be a medieval nun?

Answer 1

Around 800 years old - if you mean what you say in your question.

If you meant "How old did a woman have to be to become a nun in the middle ages", there is no specific answer since each Order and even each nunnery would have its own rules. Up to about 1216 it was common for girls to be "donated" to the local nunnery (and boys to a monastery) - they were called oblates and they could be very young indeed.

Oblates were not nuns straight away; they studied at the nun's school, learned to sew, embroidery, cook, read and write in Latin and studied the life of the nuns, learning the daily routine and the 8 services that took place every 24 hours.

At perhaps the age of 14 or 15 they could become a novice, wearing a white veil; many would have chosen instead to leave the nunnery and find employment in ordinary life. Novices might continue for a year or two (or longer) before taking their vows in front of a bishop and being made a professed nun.

Many women joined nunneries late in life; in an age without welfare support for the elderly, for widows or anyone, life in a nunnery promised security, stability and a degree of medical care not available elsewhere. Many joined in their teens because they were devoutly religious and received a calling; or were simply against the idea of marriage.