Age Calculator

Exact age is found by comparing the year, month and day of the birth date with the target date. When the day or month of the target date is earlier than the birth day or month, the calculation borrows days from the previous month and months from the previous year — correctly handling months of different lengths and leap years.

Leap years add February 29, so people born just before or on that date age slightly differently in day counts. This calculator uses real calendar arithmetic: borrowing days uses the actual length of the previous month, so leap years are handled automatically. February 29 birthdays are celebrated on February 28 in non-leap years for the countdown.

Yes. Set the "as of" date to any date after the date of birth — a future date shows how old someone will be then, and a past date shows how old they were. This is handy for eligibility checks, school admissions and retirement planning.

Some calculators divide total days by 365.25, which gives approximate months and can be off by days. Calendar-accurate calculators like this one borrow across real month lengths, so the years, months and days always add back up to the exact birth date.