Using the tools at GEDmatch
the Basics for Finding Relatives

a free third party site for DNA test comparisons and more

by Kitty Cooper, blogging at

The video of me talking about GEDmatch tools using these slides will be available as of Dec. 9 from

This talk did not cover ancestry composition (aka admix), my slides on that are

I also have many blog posts about GEDmatch, see

This slide originally had a link to the slides site -

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Basic Home Page at GEDmatch



Basic Home Page at GEDmatch

Upload your DNA results and a GEDCOM of ancestors

Click YES

While you wait for your kit to "tokenize" so you can use the ONE TO MANY tool

Run these two tools

23andme File Analysis

Family Tree DNA File Analysis

DNA File Diagnostic Utility Output



Family Tree DNA File Analysis

DNA File Diagnostic Utility Output

When you have multiple kits, mark the extras as research

Run this tool next

Basic Home Page at GEDmatch

Please upload a GEDCOM with about 10 generations of ancestors for each kit

The most important tool for finding relatives is the one to many

You may want to use 10cM or even 20cM for the minimum largest autosomal segment to make a faster and shorter list

One to Many Comparison

My Dad's One to Many Report

  • Clicking the L gives you the one to many for that kit, your match

  • Kit numbers: A ancestry, M 23andme, T family tree DNA, Z new generic

Notice gen 1.0 are his children, 1.5 nephew, 2.6 1st1R, subtract one to get the cousin level so a 3.0 is a 2nd cousin

DNA excerpt from Dad's One to Many Report

Click the A to get the autosomal one to one form for this kit and you

Click the X to get the one to one X comparison form for this kit and you

You can lower these to 500 SNPs and 6 cM

One to one with numbers and graphics (partial page)
My double third AJ cousin

One to one without the graphics
My double third AJ cousin

Siblings have fully identical regions (FIRs) - the green bars

You can select a group of kits to investigate from the one to many

There are many tools that can be run with your list of test kits

First let's look at the matrix tools

The Autosomal Matrix shows you the total centimorgans shared among your group

Generations Matrix
an easy way to see the relationships

The chromosome displays both compare everyone to the first person in the group

  • The color coding is the size range in cMs (the graph is in base pairs).

The GEDmatch 2-D Chromosome Browser

  • Each person is a different line rather than a different color
  • Old branch means that it is an overlap (not necessarily a match) to a previous person, a white line connects to that person

The 3D chromosome browser attempts to compare everyone to each other

The segments for IL and mm were less than 7cM so do not show here

The 3D chromosome browser charts

The other tools are

  • Tracebility

  • Matching GEDCOMs

  • X matrix

  • The Segment CSV

Traceability gives you a picture of who matches who as well as the generation chart again

Traceability gives you a picture of who matches who

Traceability Close Up

Matching GEDCOMs shows you which matches have trees

The Segment CSV file gives you the actual chromosomes and matches

But everyone is in there twice and there are no SNPs listed

So not the best way to add to your master spreadsheet
(more on that later)


Notice that the multiple kit analysis is available from the Home page DNA Analysis box

The ICW function:

"People who match
one or both kits"

Comparing my Dad and my 2nd cousin with threshold 8cM

My GEDmatch home page has the tier 1 utilities

A paid membership gets some extra tools called "Tier 1"

Form to do a matching segment search, enter your kit number

Part of a Matching Segment Report

All the information needed for a Master Spreadsheet is in the Matching Segment Report

Form to do a triangulation, enter your kit number

Sorted by Chromosome and Position with Graph

Sorted by Kit Number has more information and can be resorted in a spreadsheet

Extract from the Master Spreadsheet that I use for my Dad's comparisons

I put the triangulation information in the notes column and color the TGs

Relationship shared DNA at ISOGG wiki from Blaine Bettinger

Blaine Bettinger's chart from the ISOGG wiki entry on autosomal statistics, bookmark it and use it!


  • If you have at least one parent tested then you can separate what you got from each parent

  • For child kit number 'xxxx', paternal file will be generated as PxxxxP1 and maternal file will be PxxxxM1

  • If the maternal or paternal phase can be determined the values will be assigned else the original unphased values will be kept


GEDmatch Basics 2016

By Kitty Cooper

GEDmatch Basics 2016

Using the tools at GEDmatch, the Basics for Finding Relatives: a free third party site for DNA comparisons Presentation by Kitty Cooper

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