For a true ‘relationship’ to exist, there must be an ancestor who is common to both individuals. Examine the chart below, the Common Ancestor is Box 1 on the Horizontal Scale (HS) as well as Box 1 on the Vertical Scale (VS).
EXAMPLE: If you have a grandson of that common ancestor, as seen in Box 3 of the HS, and you want to know that grandson’s relationship to a great-granddaughter, seen in Box 4 on the VS.
Follow Box 4 (VS) across to where it meets the vertical pathway to Box 3 (HS), then where they cross tells you the relationship — they are first cousins once removed.
| 1 | 2 | 3 | 4 | 5 | 6 |
1 |
Common | Son | Grand | Great | 2nd Great | 3rd Great |
2 | Son | Siblings | Nephew | Grand- | Great | 2nd Great |
3 | Grand | Nephew |
First | First | First | First |
4 | Great | Grand- | First |
Second | Second | Second |
5 | 2nd Great | Great | First | Second |
Third | Third |
6 | 3rd Great | 2nd Great | First | Second | Third |
Fourth |
7 | 4th Great | 3rd Great | First | Second | Third | Fourth |
8 | 5th Great | 4th Great | First | Second | Third | Fourth |
9 | 6th Great | 5th Great | First | Second | Third | Fourth |
10 | 7th Great | 6th Great | First | Second | Third | Fourth |