Age calculator in years, months and days
Enter your date of birth to see your exact age today, or change the second date to see your age on any past or future day.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter date of birth and age on this date.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Count the whole calendar months from the birth date to the chosen date: years = months ÷ 12, the remainder is months, and days are what is left after the last whole month. When the birth day does not exist in a month (such as the 31st), the last day of that month is used.
Example
Inputs: Date of birth = 1990-05-15, Age on this date = 2026-09-30. Result: Your age: 36 years, 4 months, 15 days; Years: 36; Months: 4.
Limits and caveats
- Someone born on 29 February completes a year on 28 February in common years; some legal systems use 1 March instead.
- The count uses whole days and ignores the hour of birth and time zones.
Questions about this tool
How do I find my exact age?
Enter your Gregorian date of birth and the years, months and days appear straight away, together with the total days you have lived.
Can I work out my age on a past or future date?
Yes. Change the "Age on this date" field to any day and the result is calculated for that day.
Why is the day count not years times 365?
The calculator counts the real days on the calendar, including leap days, instead of using an average.
How do I calculate age from a date of birth?
Count the whole years, then the whole months, then the days left up to today. Example: someone born on 15 January 2000 is 26 years, 8 months and 16 days old on 1 October 2026. The calculator does this instantly and handles leap years.