Few people lived to middle age.

Although the average life expectancy was 35, many people lived beyond that. It is an exaggeration to think people did not make it to 40, and is based upon calculations which include infant mortality etc. If people lived past infancy, which was the first hurdle, and then into their twenties, which was the second hurdle then there was a very good chance a person would live into his 50s or 60s. Some even lived decades past that. So in reality, middle age wasn't that much younger than middle age today. It was often dependent upon class, of course.

The same as it is now, 40s and 50s, though far from being looked down on, it was something everybody hoped to attain, and was seen as the best time of life as it was presumed to be an age of prosperity, prominence in the community, and a time when your oldest children and servants were shouldering most of the physical burdens of life for you, but you still had your strength and wits - if not the agility and speed of youth. One can't quite compare modern and medieval life-expectancy rates. For one, modern ones don't factor in the aborted, while the medieval rates do factor in all child mortality and infanticides. Also, most modern mathematically challenged folks seem to equate averages with maximums. Stillbirths and newborn deaths aside, the fact is that even in the worst of times (except the years 1347-1349 when half the human race died) people had roughly a 50/50 chance of seeing their next decade. The dangers of childbirth made things much worse for women than men, but if they survived their childbearing years, women tended to outlive their male peers by a decade on average. What this means is that in a city of 100,000 (many of the cities of Europe were between 100k and 250k from around 1200 until the Plague years), while 75% of the population were under 40, 25k people were also over 40, 12-13k over 50, 6-7k over 60, and 3-4k over 70, and octagenarians were far from unheard of.

21?

For men, 18. For women, 12. For witches, 45, unless they got caught, then it was also 12.

Thirties and forties. Few people lived beyond sixty. +5

probably 20ish

25-35