How is this DNA match likely related to me?
Enter the total shared centimorgans and see every plausible relationship, ranked by likelihood — with the reasoning shown, so you can weigh it against your paper trail.
ranges
Step 1 · Your input
Enter the shared DNA.
Use the total shared centimorgans (cM) from the match page. Do not use the longest segment, percentage, kit number, or raw DNA.
Step 2 · Results
Results will appear here.
Enter a shared-cM value to see every relationship class in this model that can fit the number.
Step 3 · Turn it into evidence
A DNA range is a lead, not proof.
Use the result to decide what to test next. Shared matches, documentary evidence, ages, geography, and family structure do the proving.
What this tool does
It compares a total shared-cM number with published range-level DNA relationship data and lists the relationship classes that can plausibly fit.
Who it’s for
Anyone trying to place a DNA match before turning that clue into a record-based research plan.
Example input
850 cM shared with one autosomal DNA match.
Example output
Several plausible classes may appear, such as first cousin, half aunt/uncle, or great-aunt/uncle. The tool explains overlap instead of forcing one answer.
Limitations
Shared cM cannot identify direction, generation, age difference, documentary facts, or the exact common ancestor by itself.
Evidence & ethics
DNA can reveal sensitive family information. Respect living people’s privacy and test every relationship hypothesis with records and shared matches.
Endogamy and pedigree collapse
Endogamy and pedigree collapse may make a DNA match appear genetically closer than the genealogical relationship. The tool is less reliable in highly endogamous populations.
Data source
Methodology uses range-level context from the Shared cM Project 4.0, curated by Blaine T. Bettinger and hosted by DNA Painter. Percentages are not shown because this tool does not use a licensed statistical probability model.
FAQ
Questions about shared cM.
The calculator is a guide for careful research, not a relationship verdict.
What does shared cM mean?
Shared cM is the total amount of autosomal DNA two people share, measured in centimorgans.
Can shared cM prove a relationship?
No. It can suggest plausible relationship classes, but records and shared-match context are needed.
Why are several relationships possible?
Different relationships can share overlapping amounts of DNA because inheritance is variable.
How accurate is a DNA relationship calculator?
It is most useful for narrowing possibilities. It cannot replace documentary evidence or human judgment.
Does this work with endogamy?
Use extra caution. Endogamy can make matches appear closer than they are genealogically.
Does Roots Adventure upload my DNA?
No. This calculator asks only for total shared cM and runs in your browser.
Do I need an account?
No account is required to calculate, print, or export a text summary.
Where does the relationship data come from?
The model uses range-level context from the Shared cM Project 4.0 hosted by DNA Painter.