Everyday Life
Free Age Calculator
Turn a date of birth into an exact age in years, months and days - as of today or any date you choose.
Free to useNo sign-up requiredNo watermarkRuns in your browser
Last reviewed: 30 September 2026 by Vishal Senthilkumar
This free age calculator turns a date of birth into an exact age: years, months and days, not just a rounded number of years. It also shows the total days, weeks and months lived, and how long it is until the next birthday.
You can calculate age as of any date, not only today. That matters for forms and applications that ask how old someone was on a particular cut-off date - a school enrolment deadline, a visa application, an insurance policy start.
How this tool works
Enter the date of birth
Use the date field, which follows your device conventions, so there is no ambiguity about whether the day or the month comes first.
Set the "as of" date if you need to
It defaults to today. Change it to work out how old someone was, or will be, on a specific date.
Read the exact age
The headline gives years, months and days. The breakdown adds total days, total weeks, total months and the days remaining until the next birthday.
How it works
Age is counted the way people actually count it: full years first, then whole months, then leftover days. You turn a year older on your birthday, not on the day you pass 365.25 days.
That means month lengths matter. From 31 January to 28 February is one day short of a month, because February has fewer days than January. The calculator borrows days from the previous month exactly as manual counting does, so the result matches what a registrar would write down.
Leap years are handled by the underlying date arithmetic rather than by approximating a year as 365.25 days. Someone born on 29 February is treated as having a birthday on 1 March in non-leap years, which is the most common convention.
Everything is computed in your own timezone from dates alone, with no times of day involved, so the result cannot drift by a day depending on where you are.
What people use an age calculator for
- Filling in forms that ask for age in years and months, such as school enrolment or childcare registration.
- Checking eligibility against a cut-off date - many schemes ask how old you were on a specific day, not today.
- Working out a child's age in months, which is how developmental milestones are usually described in the first few years.
- Counting down to a birthday, anniversary or retirement date.
- Settling the "who is older" question precisely, down to the day.
Why two age calculators can disagree
If another tool gives a slightly different answer, it is almost always one of three things.
- Some tools divide total days by 365.25 and round. That is fine for a rough figure but drifts by a day or two, and it cannot produce a correct years-months-days breakdown.
- Some count the birth day itself as day one, others as day zero. This calculator treats the day of birth as age zero, which is the everyday convention.
- Timezone handling. Tools that work in timestamps rather than calendar dates can land on the wrong side of midnight. This one works purely in dates.
Worked examples
Born 15 March 1990, checked in September 2026
That is 36 years, 5 months and some days, depending on the exact date - along with roughly 13,300 days lived.
A baby's age in months
For an infant born in June, the total-months figure is what health visitors and milestone charts use, rather than a fraction of a year.
Age on a school cut-off date
Set the "as of" date to 1 September to see how old a child will be at the start of term, which is what most enrolment rules turn on.
A 29 February birthday
Born on a leap day, the birthday is treated as 1 March in years that have no 29 February - the usual convention for records and forms.
Frequently asked questions
Is this age calculator free?
Yes, completely free with no sign-up. The date you enter stays in your browser and is never sent to a server.
How do I calculate my exact age in years, months and days?
Enter your date of birth and leave the second date as today. The calculator counts whole years, then whole months, then the remaining days, which is how age is normally recorded.
Can I calculate age as of a past or future date?
Yes. Change the "as of" date to any date you like, which is what forms asking about a cut-off date usually need.
How does it handle leap years?
It uses real calendar dates rather than approximating a year as 365.25 days, so leap years are counted correctly. A 29 February birthday is treated as 1 March in non-leap years.
Why is my age in months not just my years times twelve?
Because months vary in length. Total months counts complete calendar months between the two dates, so it lines up with the years-and-months breakdown rather than a simple multiplication.