How old are you really?
When someone asks how old you are, you probably just give a number. But your actual age is a moving target. Depending on the day and even the minute, you are a certain number of years, months, days, hours, and minutes old. This calculator gives you all of those numbers at once.
The math is not always as simple as subtracting your birth year from the current year. Calendar months have different lengths, leap years add an extra day, and if you were born on February 29, your birthday only exists every four years. This tool handles all of that quietly behind the scenes.
How leap years and time of birth work
If you were born on February 29, the calculator treats February 28 as your birthday in non-leap years. That way your age still increases at the right pace even when February 29 does not exist.
You can also add a specific time of birth. That unlocks hours and minutes in your age, which is useful for birthdays, medical records, or just curiosity. The result accounts for your local timezone, so the numbers reflect where you actually are right now.
Example: Born on February 29, 2000. On February 28, 2026, the calculator still counts your age correctly, and on March 1 it moves forward again.
What this calculator shows you
After entering your birth date, you’ll see your age broken down into several useful formats:
Years in decimal
Your total age expressed as a decimal number, like 25.43 years.
Years, months, days
The familiar human-friendly format for your age.
Hours and minutes
If you add a birth time, the breakdown includes hours and minutes.
Total time alive
Total months, weeks, days, hours, and minutes since birth.
A few things to keep in mind
Leap years are handled for you. If you were born on February 29, the calculator already knows how to deal with it.
Timezones matter. The calculation uses your device’s local timezone, so it reflects the date and time where you are.
Nothing is stored. All calculations happen in your browser. Your birth date never leaves your device.
Frequently Asked Questions
Does this work for leap year birthdays?
Yes. If you were born on February 29, the calculator treats February 28 as your birthday in non-leap years so your age stays accurate.
Why would I add a time of birth?
Adding a birth time gives you a more precise age, including hours and minutes. It is useful for birthdays, medical contexts, or just knowing exactly how long you have been alive.
How are total months and weeks calculated?
Total months counts each calendar month you have lived through. Total weeks is simply total days divided by 7, rounded down to a whole number.
Is my birth date stored anywhere?
No. The calculator works entirely in your browser. Your birth date is not saved, uploaded, or sent to any server.