For a true "relationship" to exist, there must be an ancestor who is common to both individuals. If you examine the chart below, for example, 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 great grandson of that common ancestor, as seen in box 4 of the horizontal scale, and you want to know that great grandson's relationship to a great-great-great granddaughter, who may be seen in box 6 on the vertical scale.
If you follow box 4 down to where it meets line six, it tells you the relationship - they are second cousins twice removed!
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| 1 | Common Ancestor | Son or Daughter | Grandson or Daughter | Great Grandson or Daughter | 2nd Great Grandson or Daughter | 3rd Great Grandson or Daughter | 4th Great Grandson or Daughter | 5th Great Grandson or Daughter |
| 2 | Son or Daughter | Siblings (Brother or Sister) | Nephew or Niece | Grand Nephew or Niece | Great Grand Nephew or Niece | 2nd Great Grand Nephew or Niece | 3rd Great Grand Nephew or Niece | 4th Great Grand Nephew or Niece |
| 3 | Grandson or Daughter | Nephew or Niece | First Cousin | First Cousin Once Removed | First Cousin Twice Removed | First Cousin Three Times Removed | First Cousin Four Times Removed | First Cousin Five Times Removed |
| 4 | Great Grandson or Daughter | Grand Nephew or Niece | First Cousin Once Removed | Second Cousin | Second Cousin Once Removed | Second Cousin Twice Removed | Second Cousin Three Times Removed | Second Cousin Four Times Removed |
| 5 | 2nd Great Grandson or Daughter | Great Grand Nephew or Niece | First Cousin Twice Removed | Second Cousin Once Removed | Third Cousin | Third Cousin Once Removed | Third Cousin Twice Removed | Third Cousin Three Times Removed |
| 6 | 3rd Great Grandson or Daughter | 2nd Great Grand Nephew or Niece | First Cousin Three Times Removed | Second Cousin Twice Removed | Third Cousin Once Removed | Fourth Cousin | Fourth Cousin Once Removed | Fourth Cousin Twice Removed |
| 7 | 4th Great Grandson or Daughter | 3rd Great Grand Nephew or Niece | First Cousin Four Times Removed | Second Cousin Three Times Removed | Third Cousin Twice Removed | Fourth Cousin Once Removed | Fifth Cousin | Fifth Cousin Once Removed |
| 8 | Fifth Great Grandson or Daughter | 4th Great Grand Nephew or Niece | First Cousin Five Times Removed | Second Cousin Four Times Removed | Third Cousin Three Times Removed | Fourth Cousin Twice Removed | Fifth Cousin Once Removed | Sixth Cousin |