Skip to Content

How Many Generations are in 500 Years?

In the average family, there are about 20 generations in 500 years of ancestors. In this post, learn how we calculate this number and how to discover exactly how many generations are in your tree going back 500 years.

There are many reasons why you might be curious about the number of generations in 500 years. Perhaps you are doing family tree research and want to know how many generations you will have to explore in order to know the names of your ancestors 500 years back in time.

Or, perhaps you took a DNA test and are curious about how far back your DNA results can take you. Or hey, maybe you are just someone who just wonders about these things.

No matter the reason, you will find the information that you are looking for below.

How many years are in a generation?

For most purposes, we assume that a generation is about 25 years long. This means that every 25 years, a new generation is born.

A generation is about 25 years long because historically, people who had children usually did so a little before 25 years old, or a little after. Over the past few decades, the average age of women worldwide at childbirth has increased to about 30 years old, especially in wealthier countries.

Will we see the estimated number of years in a generation increase in the future? Perhaps so, but for now, we will stick with 25 years.

The actual length of a generation in a family will vary drastically because of many factors, which I discuss in length towards the end of this article.

How many generations are there going back 500 years?

Since each generation is about 25 years long, we simply divide 500 by 25 to determine that there are 20 generations in 500 years.

Most people can’t know exactly how many generations their family tree has in it on every line of their ancestry. This is because the majority of people cannot trace their ancestry back as far as 1521.

Five hundred years is a long time, after all.

Five hundred years ago, the world saw the fall of Tenochtitlan, which is now Mexico City. The world in 1521, which witnessed Martin Luther declared an outlaw and, possibly, the birth of Catherine Howard, Henry VIII’s future wife, was a vastly different place than it is now.

It is no wonder that most people will know little about what their ancestors might have been doing in those distant times – much less exactly how many generations have passed between now and then. In other words, it’s hard to go that far back in genealogy.

For most people, 500 years is the far end of the genealogical time frame. In addition, we have quite a few ancestors going back that far, and learning about all of them would be an incredible task – even if it were realistically possible.

Even so, some people have manged to build some lines of their family tree back far enough to measure the number of generations that have passed in this 500 year period.

buy the Family Tree Building Basics E-book

How to know exactly many generations are in your family tree over 500 years?

The best way to find out exactly how many generations are in your family tree over a 500 year period is to begin building your family tree. Not everyone will be able to go back 500 years, of course.

Even so, many people could begin to get an idea as to how often a new generation is born in their family by examining the past 150 year period. This is a very achievable goal for most people who are interested in genealogy.

Example of 500 years of generations in a real family tree

I took a look at my own family tree when I was writing this article in order to see exactly how many generations were in a real family tree over the course of half a millennium. What I found surprised me!

There is some genealogical evidence that one of my ancestors, born in Massachusetts in 1626, might have been the great-great granddaughter of Katherine Cromwell, the sister of Thomas Cromwell. Yes, that Thomas Cromwell.

This is only of the only lines of my family tree that I have managed to trace – even tentatively – back to the 1500s. Using this as an example, I can count the number of actual generations over this 500 year period in my own family tree.

When I do, I count only 15 generations. On this line of my family tree, there are only fifteen generations in 500 years.

Why are there only 15 generations instead of the “average” 20 in this particular line of my ancestry? Would it be like this in many family trees?

I went back through my family tree and calculated the age of every person in that one direct line and discovered that there were an average age of 30.86 years between generations of ancestors.

What factors make generations go by more quickly in a family tree?

As I mentioned earlier in this post, there are various reasons why there might be more or less than 20 generations in a 500 year period in any given family line. For example, as a general statement, females tend to have their children earlier in their adult life, so we might find that our female-only lines of descent have fewer years between new generations.

Cultural attitudes towards childbirth, child-rearing, and marriage could also affect how many generations we see in a particular family tree over a 500 year time period.

In other words, a culture and economy that encourage people to settle down and start families when they are in their early 20’s might see more generations in a 500 year period. Other places that have societal forces that encourage people to wait might see fewer generations in the same time period.

In addition, each individual family will be different from the next, even within a similar geographic and cultural area.


I hope that this post has helped you understand approximately how many generations there are in 500 years, how we get that number, and how you can figure out this exact number in your own family tree.

If you have any questions about a concept that was written about in this article, or if you want to share the number of generations that you counted on a line in your family tree going back 500 years (to about 1521), I would love to hear from you in the discussion below.

Thanks for stopping by!

Share the knowledge!

What is the Iberian Peninsula_ DNA Ethnicity
← Previous
What is the Iberian Peninsula: DNA Ethnicity
What To Do With Old Letters
Next →
What To Do With Old Letters

This site uses Akismet to reduce spam. Learn how your comment data is processed.