What is my brother-in-law's brother to me?
It depends on which brother-in-law. If he is your spouse's brother, his brother is your spouse's brother too (or your spouse), so he is another brother-in-law. If he is your sister's husband, his brother is your sister's brother-in-law, and English has no word for what he is to you. First names do the job.
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Sister's brother-in-law
English has no word for this person. The marriage that links you is your relative's, not yours, so they aren't your in-law, and families just say “sister's brother-in-law”.
- You
- Your sister
- Her husband
- His brother
From the other side, you are their sibling-in-law's sibling.
This connection runs through a marriage, not a shared ancestor, so the ancestor chart can't draw it.
The calculator below works out blood relationships through a shared ancestor — use it to explore the rest of your tree.
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This relationship sits outside the shared-ancestor model, so the card above carries the answer and the calculator opens in its default state. Work out any blood relationship with it, or open the full relationship calculator.
Related questions
FAQs
Is my brother-in-law's brother related to me?+
Only if your brother-in-law is your spouse's brother, and then his brother is your brother-in-law as well. Your sister's husband's brother is not your in-law.
Who am I to my sister's husband's brother?+
His sibling-in-law's sibling, which has no everyday name.
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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