Age Calculator

How is exact age calculated?

Your exact age is the number of complete years, months and days between your date of birth and a given date. Counting it by hand is fiddly because months have different lengths and leap years add a day, which is why forms that ask for age “as on” a particular date so often produce mistakes.

This age calculator gives your exact age in years, months and days on any date — today, a past date or a future cut-off — plus your age in total months, weeks and days, the day of the week you were born, and the countdown to your next birthday.

How this calculator works

Age is a calendar calculation, not a division of days by 365.25. The calculator counts complete years from your date of birth, then complete months, then the days left over — which is why the answer matches what a passport or a government form expects.

Because the arithmetic works on calendar dates, leap years and months of different lengths are handled naturally: someone born on 31 January turns a month older on 28 or 29 February, and a 29 February birthday falls back to 28 February in non-leap years.

Formula

years  = as-of year − birth year
months = as-of month − birth month      (borrow 12 if negative)
days   = as-of day − birth day          (borrow the previous month's length)

Worked example

1. Born 12 May 1994, calculated on 24 September 2026.
2. Years: 2026 − 1994 = 32. Months: September − May = 4. Days: 24 − 12 = 12.
3. Result: 32 years, 4 months and 12 days — about 11,793 days.

When you need age on a specific date

• School admission: many states set a minimum age for Class 1 (commonly six years) as on a cut-off date such as 31 March or 1 June of the admission year.
• Government jobs and exams: eligibility is judged by your age as on a date fixed in the notification — often 1 January or 1 August — including any age relaxation for reserved categories.
• Retirement: most government employees retire on the last day of the month in which they turn 60.
• Tax: you are a senior citizen for income tax once you turn 60 at any time during the financial year, and a super senior citizen at 80.
• Insurance: premiums usually depend on your age at your last or nearest birthday — check which one the insurer uses.

Assumptions & important notes

Frequently asked questions