Age Calculator
Enter your date of birth and instantly find your exact age in years, months, and days. The calculator also shows how many days remain until your next birthday.
How to use the Age Calculator
Pick your date of birth from the date input field. Your exact age appears immediately, broken down into complete years, remaining months, and remaining days. No rounding — the breakdown reflects the precise elapsed time as of today.
How age calculation works
The calculator subtracts your birth date from today's date using calendar-accurate arithmetic: it counts complete years first, then complete months within the remainder, then the leftover days. This matches how age is legally and socially defined — a person born on March 15 does not turn one year older until March 15 of the following year, not 365 days later (which would drift due to leap years).
Frequently Asked Questions
How is the exact age in years, months, and days calculated?
The calculator counts complete elapsed years from your birth date to today, then counts remaining complete months, then remaining days. Each unit uses real calendar dates rather than fixed-length approximations, so February, 30-day months, and leap years are all handled correctly.
How is the next birthday countdown calculated?
The calculator takes your birth month and day, applies them to the current year to get this year's birthday, then checks if that date has passed. If it has, next year's birthday is used instead. The difference in days from today gives the countdown.
What if my birthday is today?
If today is your birthday, the calculator will show 0 days until your next birthday and display a birthday message. The age in years will reflect your new age as of today.
Does the calculator work with all date formats?
The date picker uses your browser's native date input, which accepts dates in the standard ISO format (YYYY-MM-DD). Most modern browsers display a calendar picker that handles date selection for you.
Why might my age differ from what I expect?
The calculation is based on today's date in your local timezone as reported by your browser. If you are near midnight in a different timezone, the result may differ by a day from what you expect.