1. What is the DNA Relationship Calculator?

The Ancestry DNA Relationship Calculator estimates the degree of genetic relationship between two individuals based on shared centimorgans (cM) of DNA. It helps interpret DNA matching results from ancestry tests.

2. How Does the Calculator Work?

The calculator uses the relationship formula:

Where:

• \( R \) — Relationship coefficient (dimensionless)
• \( CM \) — Shared centimorgans (dimensionless)
• 3480 — Average total shared cM between parent and child

Explanation: The equation compares the shared DNA to the average amount shared between parent and child to estimate relationship degree.

3. Importance of Centimorgan Analysis

Details: Centimorgan values help determine biological relationships, with higher values indicating closer relationships. This is crucial for genealogy research and understanding family connections.

4. Using the Calculator

Tips: Enter the shared centimorgan value from your DNA test results. The calculator will estimate the relationship coefficient and likely relationship.

5. Frequently Asked Questions (FAQ)

Q1: What is a centimorgan?
A: A centimorgan (cM) is a unit of genetic linkage that measures the distance between chromosome positions.

Q2: How accurate are these predictions?
A: While cM values correlate with relationships, actual relationships can vary due to random DNA inheritance.

Q3: Why 3480 cM as the baseline?
A: This represents the average amount of DNA shared between parent and child (about 50% of autosomal DNA).

Q4: Can full siblings share more than 3480 cM?
A: Yes, siblings typically share about 2600-3700 cM due to recombination.

Q5: What about half-relationships?
A: Half-siblings typically share about 1300-2300 cM, roughly half of full siblings.