Age Calculator
Enter your date of birth to get your exact age in years, months and days — plus total days lived and the weekday you were born on. Free, instant, no signup.
About this tool
Knowing your exact age down to the month and day is useful more often than you might think - for official forms, birthday planning, retirement math, or just curiosity. Doing the subtraction by hand is surprisingly easy to get wrong, especially across leap years.
Our age calculator gives you an exact answer in seconds. Enter your date of birth and it tells you your age in years, months, and days, plus the total number of days you have lived and the day of the week you were born on.
How to use
Pick your date of birth from the calendar field and press Calculate Age. That is all there is to it.
The result shows three things: your precise age (for example, 27 years, 4 months, 12 days), the total days you have been alive, and the weekday of your birth. It is a fun detail to share at birthday parties - most people have no idea which day of the week they were born.
The math behind it
The calculator subtracts your birth date from today's date. It first finds the difference in years, then adjusts the months and days so the result is exact - borrowing days from the previous month when needed, just like you would on paper.
Leap years are handled automatically because the math uses real calendar dates. The total-days figure is simply the number of 24-hour periods between the two dates, and the weekday comes from the calendar itself.
Frequently asked questions
How do I calculate my exact age from my date of birth?
Does the calculator account for leap years?
Why do different age calculators sometimes disagree by a day?
What is the difference between an age calculator and a birthday countdown?
Can I calculate what my age was on a past date?
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