Using the Kinship Explorer and Relationship Calculator
Master the Kinship Explorer to calculate relationships, find common ancestors, visualise family paths, and estimate expected shared DNA between relatives.
What is kinship calculation?
Kinship calculation determines the exact genealogical relationship between two people:
- Direct relationships: Parent, grandparent, child, grandchild
- Collateral relationships: Siblings, cousins, aunts/uncles, nieces/nephews
- Removal: "Removed" refers to generational difference (first cousin once removed)
- Half relationships: Sharing one parent instead of two
Understanding these relationships is essential for interpreting DNA results and legal matters like inheritance.
Using the Kinship Explorer
Access the Kinship Explorer via Directory > Kinship Explorer. You can:
- Select two people: Search for any two individuals in your tree
- See the relationship: Get the exact genealogical term (e.g., "2nd cousin once removed")
- View the path: See the chain of relationships connecting them
- Find common ancestors: Identify the most recent common ancestor(s)
- Estimate shared DNA: See expected centimorgans based on the relationship
Understanding relationship terminology
Relationship terms can be confusing. Here's a guide:
- 1st cousins: Share grandparents
- 2nd cousins: Share great-grandparents
- 3rd cousins: Share great-great-grandparents
- Once removed: One generation apart (your 1st cousin's child is your 1st cousin once removed)
- Twice removed: Two generations apart
- Half: Share one common ancestor where full would share two (half-siblings share one parent)
Visualising relationship paths
The Kinship Explorer shows the path connecting two people:
- Standard view: Shows the chain of parent-child links
- Timeline view: Arranges people chronologically by birth year
- Common ancestor highlight: The shared ancestor is emphasised
- Marriage connections: Shows how spouses connect different lines
This visualisation helps you understand exactly how two people are related through your tree.
Shared DNA estimates
The Kinship Explorer estimates expected shared DNA based on the relationship:
- Parent/Child: ~3,400 cM (50%)
- Full siblings: ~2,550 cM (varies widely)
- 1st cousins: ~850 cM (range: 553-1,225)
- 2nd cousins: ~212 cM (range: 41-592)
- 3rd cousins: ~53 cM (range: 0-234)
- 4th cousins: ~13 cM (range: 0-139)
These estimates help you evaluate whether DNA matches align with expected relationships in your tree.
Exploring all relatives of a person
Beyond comparing two specific people, you can explore all relatives:
- Grouped by relationship type: See all cousins, all uncles/aunts, etc.
- Degree breakdown: Count how many 1st, 2nd, 3rd cousins, etc.
- Living relatives: Filter to show only those likely still alive
- Research priorities: Identify key individuals for DNA testing
This overview helps you understand your tree's structure and plan research strategically.
Using kinship for DNA research
Combine kinship calculations with DNA testing:
- Verify matches: Does the shared DNA align with the calculated relationship?
- Triangulate: When multiple matches share DNA and a common ancestor, that confirms the line
- Identify unknowns: If a DNA match shares X cM, what relationship ranges are possible?
- Plan tests: Which relatives should be tested to answer specific questions?