What percent of children grew to adulthood in medieval times?

Answer 1

I have read that about a third of all infants died and only about half of all births produced people who lived to age 20. I looked at a bunch of papers on the internet, and this seems to be more or less a consensus. I am suspicious of the things I read about the Middle Ages, because most of it turns out to be wrong, so I looked for my own information. I studied the lives of a number of important people who had children recorded in history, and it looks like the idea that half lived to 20 might be true. Of those who lived to 20, however, it seems most were still alive at 45 or 50.

Answer 2

The Death Rate of children was high and even more so when the plague hit. I am going to take a guess here at probably a good 50%, but historians think a better estimate could be 30%. There are no records that we can look at to determine this so it is just a guess.