Age Calculator in Years, Months & Days

This age calculator works out exact age in years, months and days from a date of birth, as of today or any date you choose. Alongside the age it shows the days, weeks and months lived, the date and weekday of the next birthday, the days left until it, and the star sign. For people born on February 29 you can choose whether the birthday in other years is March 1 or February 28, so the rule behind the result is always clear.

How to use

1. Pick the "Date of birth". The "Age" as of today appears in large type, with the years, months and days below it.
2. To work out the age on another date, such as a deadline, an exam or a past event, pick it under "Age on". Press "Use today" to go back to today.
3. If the birth date is February 29, choose "March 1" or "February 28" under "Birthday in non-leap years".
4. Read "Days lived" and its hint, and "Months lived" with the number of weeks below it.
5. Check the "Next birthday" with its weekday and the days "Until the next birthday".
6. The "Star sign" is shown from the birth date, together with its usual date range.

How it works

• Age starts at 0 on the day of birth and goes up by one on each birthday. Months and days are counted on the calendar from the last birthday; when a month has no such day, its last day is used (one month after January 31 is February 28).
• "Days lived" counts the days from the birth date to the chosen date; the hint adds one for counting the birthday as day 1. Weeks are whole weeks, rounded down.
• For February 29 births, March 1 is the default, as in UK and Korean practice; some places use February 28. Which rule applies to you depends on local law.
• Star sign dates follow a common newspaper table; the boundary day can shift by one from year to year.
• Everything is worked out in your browser, and the dates you enter are remembered only in this browser on this device.

How to calculate exact age in years, months and days

Subtract the birth year from the current year, then subtract one more if this year's birthday has not come yet. Someone born on June 15, 1995 is 2026 − 1995 = 31 on October 18, 2026, because the birthday has passed; the exact age is 31 years, 4 months and 3 days. Someone born on December 31, 1995 is still 30 on the same day.

The months and days are counted from the last birthday. Month ends need a rule, because months have different lengths: this calculator treats one month after January 31 as February 28, so a baby born on January 31, 2026 is 1 month and 1 day old on March 1, 2026. Other calculators may handle month ends differently and disagree by a day.

Age calculator for a leap year birthday (February 29)

In non-leap years there is no February 29, so a rule decides when the age goes up. By default this calculator uses March 1: someone born on February 29, 2004 is 21 on February 28, 2026 and turns 22 on March 1, 2026.

Many people celebrate on February 28 instead, and the legal rule differs between countries. Switch to "February 28" and the same person turns 22 on February 28, 2026. In leap years such as 2028, the birthday is February 29 whichever option you choose.

How many days old am I? Days, weeks and months lived

"Days lived" is the number of days from the birth date to the chosen date. For a birth date of June 15, 1995, it is 11,448 days on October 18, 2026, or day 11,449 if the birthday counts as day 1. That is 1,635 whole weeks and 376 whole months. A baby's first birthday is 365 days after birth, or 366 when a February 29 falls in between.

Some rules use age on a fixed date rather than today, such as a school entry cut-off, a sports age group or an application deadline. Set that date under "Age on" to see the exact age on it, and use the same field to check how old someone was on a past date.

Questions and answers

How do I calculate my exact age?

Subtract your birth year from the current year, and subtract one more if this year's birthday has not come yet. Someone born on June 15, 1995 is 30 on June 14, 2026 and 31 on June 15, 2026.

How many days old am I?

"Days lived" shows the days from your birth date to today, or to the date under "Age on". The hint below it gives the count with the birthday as day 1.

How many days until my birthday?

"Until the next birthday" shows the number of days, and "Next birthday" shows the date with its weekday. On the birthday itself it shows today.

How do I calculate age on a specific date?

Pick that date under "Age on", and the age, days lived and next birthday are worked out for it. Press "Use today" to go back.

When does someone born on February 29 turn a year older?

By default on March 1 in non-leap years. You can switch to February 28 under "Birthday in non-leap years".

How many months old is my baby?

"Months lived" shows the whole months since birth, and the line under the large age figure gives the exact age in years, months and days.

How many weeks old am I?

The line under "Months lived" gives the whole weeks lived, which is the days lived divided by 7 and rounded down.

What is my star sign by date of birth?

"Star sign" shows it with its date range. If you were born on a boundary day, check an ephemeris for your birth year, because the boundary can shift by one day.

Is my date of birth sent anywhere?

No. The age is calculated in your browser, and the dates are remembered only on this device.