The closeness of Kinship is measured in grades (grado). Each generation is a grade. The grade series determines the line which can be straight, also called direct line (from ascendants to descendants or vice versa), or “colateral” (relatives that do not descend one from another but belong to a common ascendant).

In the line, as many grades as persons are counted, subtracting one.

In the direct line you are first grade with your parents, second with your grandparents, and third with your great-grandparents.

In the direct line, you are also first grade with your sons or daughters, second grade with your grandchildren, third grade with your great grandchildren.

In the collateral you count up from the deceased to the common progenitor and then go down to the inheritance tax payer (the person for whom the count is being made). So a brother is therefore two grades from his brother, three from his uncle or aunt, and four from his cousin.