What is a Seventh Cousin?

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Do you want to know what a seventh cousin is? In this post, find the definition of a seventh cousin, how you are related, how many you have, and much more!

We don’t often think about our seventh cousins. They aren’t closely related to us, and the vast majority of people never even know the names of any of their 7th cousins.

Even so, you might come across seventh cousins in your genealogy research or when studying your family tree. If you want to know everything there is to know about your 7th cousins, you have come to the right place.

What is the definition of a seventh cousin?

Seventh cousins share great-great-great-great-great-great grandparents and are descended from different offspring of those 6th great-grandparents. In other words, your 5th great-grandparent was the sibling of your seventh cousin’s 5th great-grandparent.

While we sometimes write “seventh cousin”, we could also write it using ordinal numbers, like this: “7th cousin”. People who do a lot of family tree research often use abbreviations, such as “7C” to denote a seventh cousin.

If you and your relative are both descended from the same child of your 6th great-grandparents, then you are sixth cousins instead of seventh cousins.

It’s very easy to get this confused, as we have so many unfamiliar ancestors at this distance.

Are seventh cousins distant cousins?

Seventh cousins are considered to be distant cousins. Most genealogists consider all cousins who are more distantly related to us than third cousins to be distant cousins, including seventh cousins.

Most people don’t know their seventh cousins, and have never met one in person. That is, we don’t usually know who our seventh cousins are, so we wouldn’t know them if we saw them walking down the street.

If you live in a place where your family has lived for several generations, especially on multiple lines of your tree, you have likely encountered a seventh cousin without even knowing that you were related.

Stories about people growing up together knowing that they are 7th cousins are rare. If you know of one, please make sure to share it in the comments at the bottom of this post.

How many degrees of separation are there between seventh cousins?

There are sixteen degrees of separation, or consanguinity, between seventh cousins. We calculate this by counting back eight generations to the most recent common ancestor (the 6th great-grandparents) and then down eight generations to our seventh cousin, for a total of sixteen degrees.

Sixteen degrees of separation between relatives equals a very distant relationship. Most people would consider this to mean that there is essentially no relationship, but others consider family to be family, regardless of distance.

What is a seventh cousin once-removed?

A seventh cousin once-removed is the child of your seventh cousin, the parent of your sixth cousin, or your parent’s seventh cousin.

It’s hard to keep all of that straight, I know, but just remember that we calculate the degree of cousins by counting back from the person who is most closely descended from the common ancestor. In the case of seventh cousins, we know that the common ancestor is the great-great-great-great-great-great grandparents.

When two cousins are one generation apart on the family tree, yet share the same 6th great-grandparents, we say that they are seventh cousins once-removed.

What is a seventh-cousin twice-removed?

A seventh cousin twice-removed is a cousin who is the grandchild of your seventh cousin, or your grandparent’s seventh cousin. We call cousins who are not of the same number of generations descended from the common ancestor “removed” by the difference in generations.

In the case of 7th cousins twice-removed, there is two generations difference between the cousins.

It is very common to find 7th cousins twice-removed, since many times we are not of the same generation as our relatives.

What is a half-seventh cousin?

As I mentioned earlier in this article, seventh cousins share at least one 6th great-grandparent. If you only share one 6th great-grandparent, then you are half-seventh cousins.

Seventh cousins who share two 6th great-grandparents (i.e. a married couple) are full seventh cousins.

It is very common to have a half cousin. We all have lots of them, which means that we are all half-cousins to someone somewhere.

How many seventh cousins do you have?

The average person might have as many as 120,000 cousins. You might even have more, and you almost definitely have at least 100,000.

If you were able to get all of your seventh cousins together in a group, you would have enough people to fill the Michigan Stadium, or “Big House”, at Ann Arbor Michigan, which has a published capacity of 107,601.

That would be quite a crowd, don’t you think?

Do you share DNA with seventh cousins?

You will share DNA, or genetic material, with some of your seventh cousins, but not all of them. Because of the way that DNA is passed down through the generations, we do not share DNA with all of our relatives.

Even so, you will share at least one small segment of DNA with some of your 7th cousins that you inherited from your shared great-great-great-great-great-great grandparent(s).

I think that’s pretty neat. It is especially interesting if you consider that your common ancestor lived a few hundred years ago, yet your DNA link remains.

Out of the 120,000 seventh cousins that you might have, only about 1320 of those would show up on a DNA test. This is because there is only about a 1.1% chance of sharing DNA with any given 7th cousin.

This means that if all of your seventh cousins took a DNA test, you would only share DNA with a small percentage of them. Since it is unlikely that every single seventh cousin that you have has taken a DNA test, you are likely to only find a relatively small handful of seventh cousins through DNA testing.

Even though that “handful” of seventh cousin DNA matches might be small relative to the total number of 7th cousins that you have, it will be a pretty long list of cousins. Some of those DNA matches might be 7th cousins once or twice-removed, too.

How much DNA do 7th cousins share?

7th cousins can share as little as no DNA with each other, and as much as 50 centimorgans (about .67%). In other words, seventh cousins share between 0-.67% DNA.

In certain circumstances, it is possible to share more than 50 centimorgans (cMs) with a 7th cousin. For example, if you have a lot of endogamy in your family tree (meaning you share multiple lines of ancestors with your cousin), you might share more DNA than is typical for your seventh-cousin relationship.

Want to learn about other cousin relationships?

If you have become curious about other cousin relationships, the following links will answer all of your questions about different degrees of cousins:

• What is a first cousin?
• What is a second cousin?
• What is a third cousin?
• What is a fourth cousin?
• What is a fifth cousin?
• What is a sixth cousin?

Conclusion

I hope that this post has helped you understand what a seventh cousin is, how many you have, how to find them, and whether you are genetically related.

If you have any questions about something that you read in this post, I would love to hear from you in the discussion below.

Thanks for stopping by today!

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