What is a half-sibling?
A half-sibling is a brother or sister who shares just one parent with you rather than both. Full siblings share both parents; half-siblings share only one. The 'half' prefix carries down the tree too — the children of half-siblings are half-first-cousins.
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The calculator above is preloaded with this relationship. Change either person to work out any other connection, or open the full relationship calculator.
FAQs
Are half-siblings still legally family?+
Yes. Half-siblings are close blood relatives; 'half' only describes sharing one parent instead of two.
Does the calculator store my family details?+
No — it runs entirely in your browser. Nothing you enter is uploaded or saved on our servers.
Start with one relative and see what comes back.
Add what you remember and AncestorIQ searches for the rest. Free to build your tree for as long as you like.
No credit card needed. Your tree stays yours.
