Age on a Specific Date Calculator
Last updated: October 15, 2026
Calculate exact age in years, months and days on a selected reference date.
Exact age
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- Total elapsed days: —
- Approximate elapsed weeks: —
- Next birthday date: —
On this page
Quick summary: Calculate exact age in years, months and days on a selected reference date.
Read the method, example and limitations
Updated reference sections in this guide are in English.
Guide language: English. Updated October 15, 2026.
What this calculator estimates
Calculate exact age in years, months and days on a selected reference date.
Inputs and units
Enter Birth year, Birth month, Birth day, Reference year, Reference month, Reference day. Use the units shown. Required fields cannot be blank. Use zero only where that field and the model allow it. Select Calculate after changing the values.
Method and assumptions
Completed months are counted from the birth date. A monthly anniversary that would fall beyond the end of a month is moved to that month's last day. The remaining days are counted from that anniversary. Twelve months make a displayed year. A February 29 birthday is treated as February 28 in a non-leap year for this calculation.
Worked example
January 31, 2026 to March 1, 2026 is 0 years, 1 month and 1 day. February 29, 2024 to February 28, 2025 is 1 year.
Limitations
Calendar-age conventions can differ for legal eligibility. This tool uses the stated month-end convention; it does not determine legal eligibility.