Age calculator
Calculate your age in years, months and days from your date of birth. Choose a reference date and see the days until your next birthday.
How the age is counted
Age is counted the way people say it: completed years first, then the completed months since the last birthday, then the days left over. Someone born on 15 June 1990 is 36 years, 3 months and 14 days old on 29 September 2026. The result also shows the total number of calendar days lived, 13,255 in this example, and the date of the next birthday with the days still to wait.
Your age on any date
The second field, “Age on this date”, starts on today but accepts any day, past or future. Use it to check whether a child reaches the required age by a school cut-off date, how old you will be on a wedding day or at retirement, or how old a historical figure was when something happened. Only calendar dates matter: the hour of birth and the time zone do not change the result.
Born on 29 February
In a year without a leap day, this calculator treats 28 February as the birthday, both for completed years and for the next birthday. That is a convention, not a universal rule. Some legal systems consider that a person born on 29 February reaches a given age on 1 March in common years, so check the rule that applies when a legal age limit is at stake. Why some years have no leap day at all is explained in the century without a leap day.
Why months and days are not a fixed length
Months have 28 to 31 days, so “3 months and 14 days” is not always the same number of days; it depends on which months lie between the two dates. When you need an exact figure, for instance to compare two ages, use the calendar-day total. For other spans between two dates, the date calculator also counts weeks and weekdays.
Questions and answers
How old am I in days?
Enter your date of birth and read the “Calendar days” line. It counts every day from your birth date up to the chosen date, leap days included.
Is age counted the same way everywhere?
Not quite. In traditional East Asian age reckoning a baby is one year old at birth and everyone gains a year at New Year. South Korea switched to the international system for legal and administrative purposes in June 2023. This calculator uses the international system: zero at birth, one more year on each birthday.
Can I calculate the age of something other than a person?
Yes. Any start date works: a pet’s birthday, the day a company was founded, a wedding date or the day you started a job. The result reads as the time elapsed in years, months and days.
Calculations run in your browser. No account is needed, and your inputs are not sent to our server. Read how our clocks work.