What is a half third cousin twice removed?
A half third cousin twice removed combines the two prefixes: 'half' because the linking siblings shared only one parent, and 'twice removed' because a two-generation gap separates you. The closer of you stands four generations below the single shared great-great-grandparent and the other six.
Loading tool…
The calculator above is preloaded with this relationship. Change either person to work out any other connection, or open the full relationship calculator.
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.
What does 'twice removed' add?+
A two-generation gap between the two of you — the 'half' and the 'removed' describe different things and stack together.
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.


