Yesterday I asked about the age demographics of a medieval society. Thanks to Joseph, Todd, Patrick, CastleMike1 over on the HarnForum, I was able to find what I was looking for. Joseph sent me some population pyramids. Using that as reference while using Google books search and image search, I found this in a biology text.
Which is very much like the population pyramid of many third world countries. Like this one from Angola. Which is also a reminder that as humans we still have some work to do to make the world a better place.
So what this useful for in tabletop roleplaying games? Say you want to flesh out an entire village. Even for a small village the detail can be overwhelming. This coupled the tendency of people to pick certain numbers over others resulting in a strange looking place, like my initial pass on Kensla for Scourge of the Demon Wolf where I had 75% of the population as children. So I want a baseline to see how many old people, middle age people, and so on there on.
Nicholas over on the Harn Forum pointed out that Family Tree on Lythia.com has some stuff in it. Sure enough on the age table there is a Current Age column which is the same as a population pyramid pyramid. I don't need to break it down by year by year so I used a spread sheet and came up with this.
Just take the population of the village and multiply it by the percentage to get the number of people of each age. If you want even more detail you can use the Family Tree articles. I divided the age cohorts unevenly.
All the children 13 and under are in one group. Since most medieval started giving adult responsibilities at age 14, I made an age group from 14 to 17. Then a young adult group of 18 to 25, where most are unmarried, then a group 26 to 30 of young married couples. Most medieval men didn't start until their late twenties because margins were so thin that you had to establish yourself before getting married and have kids.
Hope this is useful in detailing your own settlements. I will clean up my spread sheet and post it.