Thanks, Noel. Here's a "quick" way I have seen it explained. You count the number of "G"'s that you have in common. If your common ancestor is Grandfather (1 G), you are 1st cousins. If your common ancestor is Great-Grandfather (2 G's), you are 2nd cousins. If your common ancestor is a Great-Grandfather (2 G's) to you and a Great-Great-Grandfather (3 G's) to the other person, then you have 2 G's in common, with one left over: that makes you 2nd cousins once removed. (Same info, just another way to calculate it.) Jenny > GREAT-GRANDFATHER > / \ > GRANDFATHER GREAT-UNCLE > / \ \ > FATHER UNCLE 1st COUSIN ONCE REMOVED > / \ \ \ > >YOU< BROTHER 1st COUSIN 2nd COUSIN > / \ \ \ > SON NEPHEW 1st COUSIN ONCE REMOVED 2nd COUSIN ONCE > REMOVED > / / \ \ > GRANDSON GRAND-NEPHEW 1st COUSIN TWICE REMOVED 2nd COUSIN TWICE > REMOVED