Age Calculator
Birth date and “as of” date — get years, months, and days between.
Dates
Age:
Total days:
How the age breakdown is calculated
The calculator counts full years, then full months within the current year, then remaining days — carrying over from the previous month when the day count would otherwise go negative, and from the previous year when the month count would go negative. This mirrors how people naturally describe age ("35 years, 4 months, 12 days") rather than just showing a single total-days figure.
Frequently asked questions
Why do different months give slightly different day counts? Months have different lengths (28–31 days), so when borrowing a month's worth of days during the calculation, the calculator uses the actual number of days in the relevant calendar month rather than a fixed 30-day assumption.
Does this account for leap years? Yes — because the calculation works directly with real calendar dates (not a fixed 365.25-day approximation), February 29th in leap years is handled automatically and correctly.
Why show total days in addition to years/months/days? Total days is useful for precise comparisons or milestone tracking (like a "10,000 days old" celebration), while the years/months/days breakdown is more intuitive for everyday use.