Irish twins calculator
Enter two sibling birth dates to see the exact age gap and whether they were born fewer than 12 months apart. Results use chronological age math — sensitive, factual, and private in your browser.
Results appear here.
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Age gap: —
Y;M;D —
Total days apart: —
Language note: “Irish twins” is informal search slang. We focus on birth spacing facts. For any two dates, the age difference calculator works the same way without that label.
Irish twins FAQ
What does “Irish twins” mean?
In casual English it usually means siblings born less than about twelve months apart. It is informal slang, not a medical diagnosis. Families use many phrases for close birth spacing.
Is the term respectful?
Some people find the phrase dated or stereotypical. We include it because people search for it, and we pair results with neutral language about birth spacing. Use whatever wording your family prefers.
How is the gap calculated?
We use the same chronological borrowing method as our age difference calculator. If the gap is under 12 months, we flag close spacing.