1. What is the Ancestry DNA Relationship Calculator?

The Ancestry DNA Relationship Calculator estimates the degree of relationship between two individuals based on the amount of shared DNA measured in centimorgans (cM). It helps determine how closely related two people might be.

2. How Does the Calculator Work?

The calculator uses the relationship formula:

Where:

• \( R \) — Relationship degree (dimensionless)
• \( CM \) — Shared centimorgans (dimensionless)
• 3480 — Base constant representing average parent-child shared cM

Explanation: The logarithmic relationship accounts for the non-linear nature of DNA inheritance patterns across generations.

3. Importance of Centimorgans in DNA Analysis

Details: Centimorgans measure genetic linkage and are used to estimate how much DNA two relatives share. More shared cM generally indicates a closer relationship.

4. Using the Calculator

Tips: Enter the shared centimorgan value from your DNA test results. Typical values range from about 3500 cM (parent-child) to under 10 cM (distant relatives).

5. Frequently Asked Questions (FAQ)

Q1: What is a centimorgan?
A: A centimorgan (cM) is a unit of genetic measurement that represents the likelihood of recombination between two markers during meiosis.

Q2: How accurate is this calculation?
A: It provides a general estimate but actual relationships can vary due to random recombination and inheritance patterns.

Q3: What's the average cM for different relationships?
A: Parent-child ~3480 cM, full siblings ~2600 cM, grandparent ~1800 cM, first cousin ~850 cM.

Q4: Why use logarithmic scaling?
A: Because DNA inheritance follows exponential decay patterns across generations, making logarithmic scaling appropriate.

Q5: Can this determine exact relationships?
A: No, it estimates relationship degree but can't distinguish between relationship types with similar cM ranges (e.g., aunt vs. half-sibling).