Age Calculator

The calculator counts whole years from your date of birth, then whole months, then the days left over. The second date starts as today, so the first result you see is your age right now. With the default birth date of 1 January 2000, on 19 October 2026 it shows 26 years, 9 months, 18 days.

Under that headline are four running totals for the same span:

Hours are calendar days times 24, so a clock change for daylight saving doesn't add or remove an hour. Leftover days are dropped from the month total, which is why 321 months isn't the whole story.

If you were born on a leap day, most years have no 29 February to reach. Here is what the tool shows for someone born on 29 February 2000:

So in a common year the calculator completes the new year of age on 1 March, not 28 February. If the exact day matters for a licence, a contract or a benefit, check the rule that applies to you, because the answer is set by local law rather than by arithmetic.

Change the Age at date field to any day, past or future. This is the field to use when a form asks how old someone is or will be on a cut-off date.

Say an applicant must be 18 on the closing date, 15 March 2026, and was born on 15 March 2008. The tool shows 18 years, 0 months, 0 days on that date, so they qualify. One day earlier, on 14 March 2026, it shows 17 years, 11 months, 27 days.

You can also look back. To find how old a grandparent was at a wedding, put their birth date first and the wedding date second.

If the second date is earlier than the first, the tool swaps them and still shows a positive age. It won't warn you, so check the order when the result looks too large.

The day total is the number of days from your birth date up to the second date. It doesn't count the day of birth itself. Someone born on 1 January 2000 is 366 days old on 1 January 2001, because 2000 was a leap year. If you want a count that includes the birth date as day one, add one to the result.

The months-and-days part works differently. Days are counted from the same day number in the last month you reached. Born on the 20th and checking on the 19th, you are a day short of a full month, and the leftover is taken from the length of the month before the second date. That is why the leftover can be 27, 29 or 30 depending on the months involved.