Date of Birth Calculator
Enter your date of birth and instantly see your exact age, the day of the week you were born, and how many days remain until your next birthday.
A true chronological age calculator
If you were born on the date you entered above, your chronological age right now is the number shown in the result card: full years, months, and days, calculated from your exact birth date to today. Chronological age is simply the time that has actually passed since birth, measured in calendar years, as opposed to how old you feel or how your body is functioning (that's called biological age, a different measurement).
This calculator gets it right down to the day by counting real calendar months and years between two dates, not a rough estimate. That matters for anything official: school enrollment cutoffs, sports age brackets, legal age checks, or medical dosing charts, all of which use chronological age, not a rounded guess.
Frequently asked questions
How accurate is this date of birth calculator?
It uses calendar-accurate date math, the same logic used in spreadsheet and calendar software, so results are precise down to the day. It also correctly accounts for leap years and varying month lengths.
Does this tool store or share my birth date?
No. The calculation runs entirely in your browser using JavaScript. Your date of birth is never sent to a server, saved in a database, or shared with anyone.
Can I calculate someone else's age, not just my own?
Yes. Enter any date of birth, past or present, and the calculator will return that person's exact age and other details.
Why does my age in months look different from years times twelve?
Because months vary in length. The calculator counts full calendar months between your birth date and today, which is more accurate than a flat multiplication.
What if I was born on February 29?
Leap day birthdays are handled correctly. In non-leap years, the calculator treats February 28 as the observed birthday for countdown purposes.