Age Calculator
Find your exact age in years, months and days from your date of birth.
How to use the Age Calculator
- Pick your date of birth.
- Optionally set an "age at" date (defaults to today).
- See your exact age, total days lived and days until your next birthday.
Age = difference between date of birth and the chosen date, in years, months and days
About the Age Calculator
This takes a birth date and an "age at" date (today unless you change it) and splits the gap into years, months and days. It works the way you would on paper: subtract the years, then the months, then the days — and when the day count comes out negative, borrow the length of the month immediately before your "age at" date. That borrowing step is why the answer tracks real calendar months rather than assuming every month is 30 days long. It also reports total days lived, the one figure here with no convention attached to it.
The years-months-days split is genuinely ambiguous, which is worth knowing before you trust the last number. Months differ in length, so "one month after 31 January" has no single correct answer. Leap days are the same story: someone born on 29 February has no birthday in a common year, so a rule must be picked. This engine rolls it to 1 March — enter 29 February 2004 and on 28 February 2026 it still says 21, ticking over to 22 the next day. That is a convention, not a fact; other tools legitimately choose 28 February.
Use this for an age from a birth date. For the raw span between two arbitrary dates, the date difference calculator is the honest tool, and due dates have their own page.
Frequently asked questions
Does it handle leap years?
Yes — it reads real calendar dates, so leap days are counted in the total. For a 29 February birth date in a common year it treats 1 March as the birthday, so the age increments then. Some calculators use 28 February instead; neither is wrong, it is a choice.
Can I get someone's age on a past or future date?
Yes. Set the "age at" field to any date and it calculates as of that day instead of today. Leave it blank and it uses today. A birth date later than the "age at" date is rejected rather than shown as a negative age.
Why does my age here differ from "this year minus my birth year"?
Because that shortcut ignores whether your birthday has happened yet. If you were born in June 1995, the shortcut says 31 all year, but you are only 31 from June onward. This calculator compares the full date.
Which number should I trust most?
Total days lived. It is a plain elapsed-time count with no convention baked in. The years-months-days breakdown depends on the borrowing rule described above, which is why two calculators can disagree by a day on awkward dates.
How is "next birthday" worked out?
It takes your birth day and month in the current year, and rolls forward a year if that date has already passed. For 29 February births the same 1 March convention applies in common years.
Guides & articles about this tool
How to Calculate Your Exact Age in Years, Months and Days
You can calculate your exact age in years, months and days by subtracting your birth date from today’s date. This guide shows you how to do it yourself, s…