What is a half third cousin?
A half third cousin is a third cousin related through half-siblings. Where full third cousins descend from a shared couple, half third cousins share just one great-great-grandparent, because the linking siblings had only one parent in common. Genetically, half third cousins are about half as related as full ones.
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FAQs
How many great-great-grandparents do half third cousins share?+
Just one. Full third cousins trace back to a shared couple; half third cousins trace back to a single shared great-great-grandparent.
Are half third cousins blood relatives?+
Yes — about half as closely related as full third cousins, because only one great-great-grandparent is shared.
Does the calculator store my family details?+
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