Relationship Chart
The chart below shows you how to determine the relationship between two people who have a common ancestor. If they do not have at least one ancestor in common, then they are not related. In the chart the common ancestor is box 1 on the horizontal scale as well as box 1 on the vertical scale.
Let us suppose that you have a grandson of that common ancestor, as seen in box 3 of the horizontal scale, and you want to know that grandson's relationship to a great great granddaughter, who would be seen in box 5 on the vertical scale.
If you follow box 5 (vertical scale) down to where it meets the vertical pathway to box 3 on the horizontal scale, then where those paths cross, it tells you the relationship -- they are first cousins twice removed.
The chart shows the details for an ancestor up to nine generations earlier than the people concerned, but the same principle can be carried back as far as you like, provided you ahve the necessary information.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
| 1 | Common Ancestor | Son or Daughter | Grandson or Daughter | Great Grandson or Daughter | Great Great Grandson or Daughter | Great Great Great Grandson or Daughter | Great Great Great Great Grandson or Daughter | Great Great Great Great Great Grandson or Daughter | Great Great Great Great Great Great Grandson or Daughter | Great Great Great Great Great Great Great Grandson or Daughter |
| 2 | Son or Daughter | Siblings (Brother or Sister) | Nephew or Niece | Grand Nephew or Niece | Great Grand Nephew or Niece | Great Great Grand Nephew or Niece | Great Great Great Grand Nephew or Niece | Great Great Great Great Grand Nephew or Niece | Great Great Great Great Great Grand Nephew or Niece | Great Great Great Great Great Great Grand Nephew or Niece |
| 3 | Grandson or Daughter | Nephew or Niece | First Cousins | First Cousins Once Removed | First Cousins Twice Removed | First Cousins Three Times Removed | First Cousins Four Times Removed | First Cousins Five Times Removed | First Cousins Six Times Removed | First Cousins Seven Times Removed |
| 4 | Great Grandson or Daughter | Grand Nephew or Niece | First Cousins Once Removed | Second Cousins | Second Cousins Once Removed | Second Cousins Twice Removed | Second Cousins Three Times Removed | Second Cousins Four Times Removed | Second Cousins Five Times Removed | Second Cousins Six Times Removed |
| 5 | Great Great Grandson or Daughter | Great Grand Nephew or Niece | First Cousins Twice Removed | Second Cousins Once Removed | Third Cousins | Third Cousins Once Removed | Third Cousins Twice Removed | Third Cousins Three Times Removed | Third Cousins Four Times Removed | Second Cousins Five Times Removed |
| 6 | Great Great Great Grandson or Daughter | Great Great Grand Nephew or Niece | First Cousins Three Times Removed | Second Cousins Twice Removed | Third Cousins Once Removed | Fourth Cousins | Fourth Cousins Once Removed | Fourth Cousins Twice Removed | Fourth Cousins Three Times Removed | Fourth Cousins Four Times Removed |
| 7 | Great Great Great Great Grandson or Daughter | Great Great Great Grand Nephew or Niece | First Cousins Four Times Removed | Second Cousins Three Times Removed | Third Cousins Twice Removed | Fourth Cousins Once Removed | Fifth Cousins | Fifth Cousins Once Removed | Fifth Cousins Twice Removed | Fifth Cousins Three Times Removed |
| 8 | Great Great Great Great Great Grandson or Daughter | Great Great Great Great Grand Nephew or Niece | First Cousins Five Times Removed | Second Cousins Four Times Removed | Third Cousins Three Times Removed | Fourth Cousins Twice Removed | Fifth Cousins Once Removed | Sixth Cousins | Sixth Cousins Once Removed | Sixth Cousins Twice Removed |
| 9 | Great Great Great Great Great Great Grandson or Daughter | Great Great Great Great Great Grand Nephew or Niece | First Cousins Six Times Removed | Second Cousins Five Times Removed | Third Cousins Four Times Removed | Fourth Cousins Three Times Removed | Fifth Cousins Twice Removed | Sixth Cousins Once Removed | Seventh Cousins | Seventh Cousins Once Removed |
| 10 | Great Great Great Great Great Great Great Grandson or Daughter | Great Great Great Great Great Great Grand Nephew or Niece | First Cousins Seven Times Removed | Second Cousins Six Times Removed | Third Cousins Five Times Removed | Fourth Cousins Four Times Removed | Fifth Cousins Three Times Removed | Sixth Cousins Twice Removed | Seventh Cousins Once Removed | Eighth Cousins |