This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Find out more here.

Average percent DNA shared between relatives

The following table summarizes the average percent DNA shared for different types of relationships according to our simulations. You may notice that several relationships share the same average percent DNA; this can account for a predicted relationship of aunt/niece for a pair of half sisters.

Relationship Average % DNA Shared Range
Identical Twin 100% N/A
Parent / Child
Full Sibling
50% Varies by specific relationship  
Grandparent / Grandchild
Aunt / Uncle
Niece / Nephew
Half Sibling
25% Varies by specific relationship
1st Cousin 12.5% 7.31% - 13.8%
1st Cousin once removed 6.25% 3.3% - 8.51%
2nd Cousin 3.13% 2.85% - 5.04%
2nd Cousin once removed 1.5% 0.57% - 2.54%
3rd Cousin 0.78% 0.3% - 2.0%
4th Cousin 0.20% 0.07% - 0.5%
5th Cousin 0.05% Variable
6th Cousin 0.01% Variable

To learn more, visit the International Society of Genetic Genealogy website.

Still have questions? Contact Us

Submit a request



Mon - Fri
3am - 8pm PT
Sat - Sun
8am - 4pm PT
Was this article helpful?
649 out of 706 found this helpful