What is a half second cousin?
A half second cousin is a second cousin related through half-siblings. Where full second cousins descend from a shared couple, half second cousins share just one great-grandparent, because the linking siblings had only one parent in common. Genetically, half second cousins are about half as related as full ones.
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FAQs
How many great-grandparents do half second cousins share?+
Just one. Full second cousins trace back to a shared couple; half second cousins trace back to a single shared great-grandparent.
Are half second cousins blood relatives?+
Yes — about half as closely related as full second cousins, because only one great-grandparent is shared.
Does the calculator store my family details?+
No — it runs entirely in your browser. Nothing you enter is uploaded or saved on our servers.
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