DNA Match Relationship Calculator
Estimate the likely family relationship from shared centiMorgans (cM) and DNA segments.
Inputs
Results
Shared DNA %
12.5%
Relationship Code (1-10)
6
How to Use This Calculator
- Enter the Shared centiMorgans (cM) from your DNA testing company's match report.
- Enter the number of Shared Segments and the Largest Segment in cM.
- Enter the Total Genome Size in cM (typically around 3,400 cM for most testing companies).
- Review Shared DNA Percentage and the most Likely Relationship classification.
- Check Confidence Score and Generations Apart to determine whether to prioritize this match.
How the result changes with Total Genome Size (cM)
| Total Genome Size (cM) | Shared DNA % | Relationship Code (1-10) |
|---|---|---|
| 5,300 | 16.04% | 6 |
| 6,050 | 14.05% | 6 |
| 6,950 | 12.23% | 6 |
| 7,700 | 11.04% | 6 |
What each input means
- Shared centiMorgans (cM)
- Total shared DNA in centiMorgans from your DNA test results
- Shared Segments
- Number of shared DNA segments reported by the testing company
- Largest Segment (cM)
- Size of the largest shared DNA segment in cM
- Total Genome Size (cM)
- Total autosomal DNA in cM (default ~6,800 is standard)
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersShared centiMorgans (cM) = 850, Shared Segments = 25, Largest Segment (cM) = 70, Total Genome Size (cM) = 6800 = 4 input(s) provided
- Calculate Shared DNA %Shared DNA %12.5 = 12.5%
- Calculate Relationship Code6 = 6
- Calculate Generations Apart0 = 0
- Calculate Confidence ScoreConfidence Score = min(10075 = 75
Engine last updated .
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