Age Calculator
Enter a date of birth to see the exact age in years, months and days, the total in months, weeks and days, the next birthday, and the dates of the 18th and 21st birthdays.
- Total months
- Total weeks
- Total days
- Total hours
| Born on a | |
|---|---|
| Next birthday | |
| Turned or turns 18 on | |
| Turned or turns 21 on |
Runs in your browser. What you enter here is not sent to our server.
How to calculate an age
- Enter the date of birth.
- Leave the second date as today, or change it to find the age on a past or future date, such as a school cut-off or an application deadline.
- Read the result. Everything updates when you change either date.
How the calculation works
The calculator counts whole years first, then whole months, then the remaining days, the way ages are normally stated. Leap years and the different lengths of months are handled by the calendar itself, not by an average.
Someone born on 29 February has a birthday only in leap years. In other years this calculator treats 28 February as the birthday. Some countries legally use 1 March instead, so check the local rule where an exact legal date matters.
Checking a minimum age
The “turns 18” and “turns 21” rows show the date of those birthdays and whether they have passed on the date you chose. That makes it quick to check whether someone meets an age requirement on a particular day. Minimum ages differ by country and by activity, so confirm the rule that applies.
Questions about the Age Calculator
Is my date of birth stored?
No. The calculation happens in your browser and nothing you enter is sent to our server.
Why does another calculator show a different number of days?
Total days should always match. Differences in the months-and-days part come from how the leftover days in a partial month are counted; this tool borrows the length of the month before the end date, which is the common convention.
Can I calculate the time between any two dates?
Yes. Put the earlier date in the first box and the later date in the second.
Can this verify someone’s age officially?
No. It does arithmetic on the date you type in. It cannot confirm that the date is true, so it is not a substitute for checking an identity document.