How to use the age calculator
- Enter the date of birth.
- Leave "Age on" as today, or choose another date.
- See the exact age in years, months and days, totals in months, weeks, days and hours, and a countdown to the next birthday.
Common uses
- Checking age requirements for school admission, sports leagues, visas or retirement.
- Filling in forms that ask for age in years and months.
- Finding out what day of the week you were born, and how many days old you are.
Age in different cultures
This calculator uses the international age system, where you are 0 at birth and gain a year on each birthday. Some East Asian traditions count differently, but official documents in nearly every country use the system shown here.
Related: Days Between Dates, Time Zone Converter.
How age in months and days is counted
The calculator first counts complete years since the date of birth, then complete months since the last birthday, then the remaining days. For example, someone born on 15 May 1990 is 36 years, 5 months and 28 days old on 12 November 2026. When the day of birth doesn’t exist in a shorter month, such as the 31st, the remaining days are counted from the end of the previous month, which matches how most official forms calculate age.
Age requirements in everyday life
- School entry: many school systems use a cut-off date, such as being 5 by 1 September. Set the “Age on” date to the cut-off to check eligibility.
- Sports and competitions: age groups are usually based on age on a specific date or at the end of the calendar year.
- Travel and visas: child fares and visa rules often depend on age on the date of travel.
- Retirement and pensions: eligibility can depend on reaching an exact age in years and months.
Days alive and milestone birthdays
The total days figure tells you how many days have passed since birth, which makes it easy to plan milestone celebrations such as 10,000 days (about 27 years and 4 months) or 1,000 weeks (just over 19 years). The countdown shows how many days remain until the next birthday and which day of the week it falls on.
Age in other units
Besides years, months and days, the calculator shows your age as total months, weeks, days and approximate hours. These are useful for pediatric milestones (often given in months until age 2), for fun facts on birthday cards, and for checking requirements written in days, such as some insurance and benefit rules.
Frequently asked questions
How is exact age calculated?
We count full years since the birth date, then the full months since the last birthday, then the remaining days. This is the same way age is calculated on official documents.
What if I was born on February 29?
In non-leap years the birthday countdown uses February 28.
Can I calculate age on a future or past date?
Yes. Change the "Age on" date to find out how old someone was, or will be, on any date, for example for school entry or retirement eligibility.