Free GEDmatch Tool

One-to-One Autosomal DNA Comparison

one to one hero image

Get personalised insights into your ancestry

Visual representation of shared autosomal DNA segments

Easy to use: simply enter two kit numbers and view the results

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Detailed DNA comparisons

Conduct detailed comparisons of two DNA profiles, with results based on default thresholds or on thresholds you specify.

Estimate the number of generations that separate you from another user

Estimate the number of generations that separate you from another user.

common traits
connect with matches

See a list of shared chromosomes and nearby matches

Use our simple visual representation of shared autosomal DNA segments, with blue segments indicating significant DNA shared between you and your match.

How To Use The One-To-One GEDmatch Tool?

The GEDmatch One-to-One tool lets us examine the details of our DNA and compare it to our matches by comparing chromosomes.

The information One-To-One GEDmatch tool helps you learn just how closely related you are to your matches and demystify family tree questions! If you share many small segments with a DNA match this could mean being related in several ways. Longer segments show an earlier ancestor than shorter segments.

1 Log in to your GEDmatch account

To use your One-To-One Tool, you first need to log in to your GEDmatch account.

The One-to-One tool is located under the “DNA Applications” title on the right side of your GEDmatch dashboard, which is the screen you see after signing into your account.

Enter the following information:

  • Your kit number
  • The kit number of the person you would like to compare DNA results
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2 Select your preferred Visual
selecting preferred visual

The Tool has its own default settings; you do not need to adjust anything else unless you want to update it.

The ‘default results’ setting is “Graphics and Position” but you can change that to a list by selecting “Position only” or to a visual graph by selecting “Graph only”.

Once you’ve selected your preferred visual – click Submit.

3 View your results

After you submit the required information on the tool page, you will be able to view the results of the comparison. If there are no matching DNA segments found between you and someone else, you will see a message that says “No shared DNA segments found”.

If you have matching DNA segments with your match, the results will look much like a spreadsheet. It might be just one DNA segment, or there could be multiple segments.

one to one results
What do GEDmatch One-to-One Results Mean?

Each person has 22 numbered chromosomes. The results above show that the two people share 12 DNA segments on 10 of their 22 chromosomes.

These two users have:

  • The largest shared DNA segment of 34.9 cMs
  • 158.8 cMs of shared DNA (of combined segments above 7 cMs in length)
  • An estimated distance to the most recent common ancestor of 3.2 generations
Breakdown of how to read one to one results
Why Use Graphics?

In cases where you are closely related to a match (such as being a sibling), it may be interesting to compare half-identical regions to entire identical regions. Everyone has 22 numbered chromosomes, and two copies of each chromosome.

One copy of each chromosome, or around 50% of our parents’ DNA, was passed down to us from each of our parents.

The 50% of our parents’ DNA that our siblings also inherited will not be the same 50% that we inherited.

Some of them will be identical and overlap in “completely identical regions,” which are those where the DNA from both the mother and the father is present.

one to one results graphic

Because most of our DNA matches are only linked to us on one side of the family, we only share “half-identical” areas with them.

The color-coded key towards the top of the results page for your GEDmatch tool designates these several regions.

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