Age Calculator
Find out an exact age in years, months and days from a date of birth, plus the total number of days lived.
Defaults to today
Enter a valid date of birth.
How it works
Enter a date of birth and the tool calculates the exact age broken down into years, months and days. By default it uses today's date, but you can set any reference date to find out an age on a specific day — useful for a future birthday or a past event.
The calculation respects the real calendar: months with different numbers of days, leap years and the rollover between months. It doesn't just divide the total days by 365; it walks the calendar properly so the breakdown into years, months and days is accurate.
It also shows the total number of days between the two dates, a fun and sometimes useful figure. Everything is computed in your browser the moment you fill in the fields.
When to use
Calculating an exact age has more uses than it seems. Filling out forms that ask for a precise age, checking eligibility for something with an age requirement, or simply satisfying curiosity about how many days someone has been alive.
It's handy for parents tracking a baby's age in months, for planning milestone birthdays, for documents that need an age on a specific date, and for anyone who wants the breakdown into years, months and days rather than just the round number of years. The reference-date option makes it easy to answer "how old will I be on…" questions too.
Practical examples
Exact age today
Someone born on March 15, 1990 has, as of a date in mid-2026, an age of about 36 years, 3 months and a few days — far more precise than just "36".
A baby in months
For a baby born a few months ago, the breakdown into months and days is exactly what parents track. The tool shows, for instance, "0 years, 7 months and 12 days" without any manual counting.
Common mistakes
The most common mistake is calculating age by simply subtracting the birth year from the current year. That ignores whether the birthday has already happened this year — someone can share a birth year with a peer and still be a year apart in exact age.
Another slip is ignoring leap years. Calculations that cross February 29 can be off by a day if you count by hand. The tool uses the real calendar, so leap years are handled correctly.
There's also confusion about how months are counted. "One month" isn't always 30 days, since months vary in length. The breakdown here follows the calendar, which is why the number of days in a month can shift depending on the dates involved.
Frequently asked questions
How do I calculate my exact age?
Enter your date of birth and, by default, today's date is used as the reference. The tool shows your age in years, months and days, plus the total days lived.
Does the calculator account for leap years?
Yes. It uses the real calendar, so calculations that pass through February 29 in leap years are handled correctly, without a one-day error.
Can I calculate age on a past or future date?
Yes. Change the reference date to any day and the tool shows the age on that date — useful for a future birthday or an age at a past event.
Why isn't one month always 30 days?
Because months have different lengths, from 28 to 31 days. The breakdown follows the calendar, so the number of days in the "months" part depends on the exact dates.