What is % Shared DNA on Ancestry?

Have you seen % Shared DNA on your Ancestry match list? In this post, learn what percent shared DNA means, and how to use this information to figure out your connection with your DNA matches.

The percentage of shared DNA showing up on the Ancestry DNA match list is a new feature for 2020. I’m always a fan of being able to learn more information about my connection with DNA matches.

The more information, the better, as the saying goes. Plus, understanding the percent of shared DNA can help us visualize how much genetic material we share with our matches.

Below, find out exactly what % shared means on Ancestry, as well as:

• What percentage of shared DNA is significant on Ancestry
• How to use this information to estimate your relationship to your DNA match
• % of shared DNA expected for various common relationships

These concepts are very easy to understand once you know the basics. With the information that you learn below, you’ll be able to confidently explore your Ancestry DNA match list.

What does % shared DNA actually mean?

The percent (%) of shared DNA shown on Ancestry is the percentage of your total DNA that is identical to your DNA match. This number is helpful in determining how we are related to our DNA matches.

Higher percentages of shared DNA usually indicates a closer relationship. In addition, there are typical ranges of shared DNA that we see for any given relationship.

How to find the percent shared DNA on Ancestry?

You can see the percentage of DNA shared with your match directly on your DNA match list. The number will appear under your estimated relationship, as show in the image below.

The DNA match above is the great-granddaughter of the test taker. They share 785 cMs of DNA with each other, which happens to be about 11% of their total DNA.

What percentage of shared DNA is significant for Ancestry DNA matches?

For the purposes of genealogy and family relationships, a significant percentage of shared DNA is 1% or higher. This is because we define third cousins, who share .3-2% of their DNA with us, as close relatives.

Thus, we can view anyone who shares at least 1% of their DNA with us as a potentially close relative. Of course, the closer the relative, the more significance to us the shared DNA will have.

Generally speaking, the higher percentage of DNA that you share with your DNA match, the closer the relationship. This is especially true when referring to close relatives.

Percentages shared with distant cousins are not as significant when trying to figure out how you might be related. This is almost always true, unless the percentage of DNA shared suggests a much closer relationship than previously known.

For example, you might have a fourth cousin who shares a slightly higher percentage of DNA with you than a third cousin. How is this possible?

There is a range of shared DNA that we expect to see between relatives. It is possible for third cousins to share very little DNA, or no DNA at all, meaning that a fourth cousin might share slightly more.

Expected percentage (%) shared DNA for common relationships

Fortunately, we know a lot about how much DNA people of most relationships share with each other. We have enough data to determine the expected percentage (%) shared DNA for a number of common relationships.

The percentages below are averages. It is possible to share slightly more or less DNA than than what you see in the table below:

Parent/Child	50%
Full Siblings	33-50%
Half-Siblings	18-33%
Grandparent/Grandchild	18-33%
Aunts/Uncles	18-33%
First cousins	8-18%
Second Cousins	1-5%
Third Cousins	0-2%

As you can see from the table above, we share a considerable amount of DNA with our parents (about 50%). More distant relatives share dramatically less DNA with us.

How to use shared % to estimate your relationship to someone

You can use the percentage of shared DNA, along with the number of centimorgans you share, to determine how far back in your family tree you should look to find your common ancestor. The higher the percentage of shared DNA, the more recent the common ancestor.

For example, if you share less than 2% of your DNA with your DNA match, you might be as distantly related as second or third cousins. This means that you should be looking back to your great-grandparents, or even your great-great grandparents in order to determine how you are connected.

If you share a much higher percentage of DNA, such as 25%, it is likely that your parents or grandparents are the common ancestor between you and your match. For closer matches, you can eliminate some relationship possibilities depending on your age, the age of your match, and other known details about your family members.

More distant DNA matches, such as those matches who share less than 1% of their DNA with us, can be more difficult to research. They could be as closely related as a half-second cousin, or as distantly related as a fourth cousin.

Conclusion

I hope that this post has helped you learn more about the meaning of % shared DNA on Ancestry, as well as how to use this information to estimate your relationship to your DNA match.

If you have any questions about something that you read in this post, or if you would like to ask a specific question about shared percentages of DNA, I would love to hear from you in the discussion below.

Thanks for reading today!

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