For a true "relationship" to exist there must be an ancestor who is common to both individuals. If you examine the chart below, the Common Ancestor is Box 1 on the horizontal scale as well as Box 1 on the Vertical Scale.
Suppose you have a grandson of that common ancestor as seen in Box 3 of the horizontal scale, and you want to know what that grandson's relationship to a great-grandson who would be seen in Box 4 on the vertical scale.
If you follow Box 4 on the horizontal scale down to where it meets the vertical pathway to Box 3 on the horizontal scale, then the box where those paths cross will tell you their relationship - they are First Cousins Once Removed.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| 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 | 6th Great Grandson or Daughter | 7th 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 | 5th Great Grand Nephew or Niece | 6th 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 | First Cousin Six Times Removed | First Cousin Seven 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 | Second Cousin Five Times Removed | Second Cousin Six 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 | Third Cousin Four Times Removed | Third Cousin Five 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 | Fourth Cousin Three Times Removed | Fourth Cousin Four Times 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 | Fifth Cousin Twice Removed | Fifth Cousin Three Times Removed |
| 8 | 5th 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 | Sixth Cousin Once Removed | Sixth Cousin Twice Removed |
| 9 | 6th Great Grandson or Daughter | 5th Great Grand Nephew or Niece | First Cousin Six Times Removed | Second Cousin Five Times Removed | Third Cousin Four Times Removed | Fourth Cousin Three Times Removed | Fifth Cousin Twice Removed | Sixth Cousin Once Removed | Seventh Cousin | Seventh Cousin Once Removed |
| 10 | 7th Great Grandson or Daughter | 6th Great Grand Nephew or Niece | First Cousin Seven Times Removed | Second Cousin Six Times Removed | Third Cousin Five Times Removed | Fourth Cousin Four Times Removed | Fifth Cousin Three Times Removed | Sixth Cousin Twice Removed | Seventh Cousin Once Removed | Eighth Cousin |