The Shared cM Project 4.0 tool v4

March 2020

Blaine T. Bettinger

www.thegeneticgenealogist.com

More about this project

CC 4.0 Attribution License

Interactive version v4 by Jonny Perl at DNA Painter

Click here to contribute data to the shared cM project

Last updated 26th March 2020

Important

• For relationships more distant than Half 2C, the averages were determined only for relationships in which DNA was shared.

• The more distant a relationship, the more likely it is that you won't share DNA at all (read more)

• These statistics do not cater for pedigree collapse or endogamy

Other versions

New: with option to add a second amount
Beta with updated probabilities
With editable boxes
Shared cM 3.0 (2017) version

Enter the total number of cM for your match:

reset or enter %

Or enter the total % shared with your match:

(cMs calculated based on a total of 7,440cM as used by 23andme)

Then any relationships that fit will stand out below
You will need to scroll the page to the right to see all relationships Click here for a shareable link to the cM amount above

It's still possible that you are related to a match with whom you share no detectable DNA...

Important: you entered centimorgans, a very low match.

Is actually the *percentage* of DNA you share?

If so, please click here to see the correct page.

Most distant common ancestors

Assuming no pedigree collapse or endogamy, and that you're related in just one way, the furthest back you might need to go to find common ancestors for a match of cM is

A match of cM has a wide range of possible relationships. The connection may be within 8th-Great-Grandparent level, but the common ancestors could also be 20 or more generations back.

Relationship probabilities (based on stats from The DNA Geek)

Click on any relationship to view a histogram

New: View these relationships in a tree

Enter a number above to see probabilities

How to read this chart

RelationshipAverageRange
(low to high;
99th percentile)

Great-Great-Great-Grandparent
GGGG Aunt / Uncle
Great-Great-Grandparent
GGG Aunt / Uncle
Half GG-Aunt / Uncle208103 – 284
Great-Grandparent887485 – 1486
Great-Great-Aunt / Uncle420186 – 713
1C3R11725 – 238
2C3R510 – 154
Other Relationships
Half 1C2R12516 – 269
Half Great-Aunt / Uncle431184 – 668
Grandparent1754984 – 2462
Great-Aunt / Uncle850330 – 1467
1C2R22133 – 471
2C2R710 – 244
3C2R360 – 166
6C180 – 71
Half 2C1R660 – 190
Half 1C1R22462 – 469
Half Aunt / Uncle871492 – 1315
Parent34852376 – 3720
Aunt / Uncle17411201 – 2282
1C1R433102 – 980
2C1R12214 – 353
3C1R480 – 192
4C1R280 – 126
6C1R150 – 56
Half 3C480 – 168
Half 2C12010 – 325
Half 1C449156 – 979
Half Sibling17591160 – 2436
Sibling26131613 – 3488
SELF
1C866396 – 1397
2C22941 – 592
3C730 – 234
4C350 – 139
5C250 – 117
6C2R130 – 45
Half 3C1R370 – 139
Half 2C1R660 – 190
Half 1C1R22462 – 469
Half Niece / Nephew871492 – 1315
Niece / Nephew17401201 – 2282
Child34872376 – 3720
1C1R433102 – 980
2C1R12214 – 353
3C1R480 – 192
4C1R280 – 126
5C1R210 – 80
7C140 – 57
Half 3C2R270 – 78
Half 2C2R480 – 144
Half 1C2R12516 – 269
Half Great-Niece / Nephew431184 – 668
Great-Niece / Nephew850330 – 1467
Grandchild1754984 – 2462
1C2R22133 – 471
2C2R710 – 244
3C2R360 – 166
4C2R220 – 93
5C2R180 – 65
7C1R120 – 50
Half 3C3R
Half 2C3R
Half 1C3R600 – 120
Half GG-Niece / Nephew208103 – 284
Great-Great-Niece / Nephew420186 – 713
Great-Grandchild887485 – 1486
1C3R11725 – 238
2C3R510 – 154
3C3R270 – 98
4C3R190 – 60
5C3R130 – 30
8C110 – 42

Submissions for the relationship “”

No histogram is available for this relationship

How to read this histogram