Age Calculator
Calculate exact age in years, months, and days from any birthdate, including today's precise day count.
About Age Calculator
An age calculator answers the surprisingly fiddly question of exactly how old someone is, in years, months, and days, from a birthdate. Hand-counting gets unreliable fast once spans cross month boundaries and leap years, and 'as of' dates other than today complicate things further.
The tool computes in full calendar units: it subtracts years, then months, then days, borrowing from the next unit when needed, exactly the way people usually state age. Leap days are handled naturally because the logic works on real calendar dates. The total-day count includes every day between the two dates, which is precise but not the same as calendar years and months.
Parents and families use it for birthdays and milestone anniversaries, HR and admin staff verify ages on forms and documents, and anyone planning a 10,000-day-style milestone uses the total-day count. Legal and medical contexts often need an exact age as of a specific date, which the custom 'as of' option provides.
How to Use
- Enter your date of birth.
- Adjust the 'as of' date if needed (defaults to today).
- Read your exact age in years, months, and days.
Example
Born January 1, 2000, as of January 1, 2026 26 years · 0 months · 0 days
The calculator accounts for calendar months and leap years, not just raw day counts.
FAQ
How are leap years handled?
The calculation uses calendar-aware logic, so February 29 birthdays and leap-day spans are handled correctly.
Can I calculate age for a past date?
Yes, set a custom 'as of' date to find someone's age on any historical date.
What's the 'days since birth' number for?
A precise total-day count is useful for milestones like 10,000 days alive, and it's fun to check.
How does the calculator handle people born on February 29?
Leap-day birthdays are handled by calendar-aware logic: in non-leap years the birthday is observed on February 28 or March 1 depending on the convention used, so the reported age stays correct.
Can I find the age of someone who is no longer living?
Yes. Set the 'as of' date to the person's date of death, or any historical date, and the tool returns the exact age in years, months, and days at that moment.