Age Calculator
Enter your date of birth to see your exact age in years, months, and days, plus a birthday countdown and fun facts about your life in numbers.
How to Use the Age Calculator
How Age Is Calculated
Age is calculated by finding the difference between the birth date and the reference date. Years are counted by how many full calendar years have passed. Months are the remaining full months after years are subtracted. Days are the remaining days after months are counted back.
The birthday countdown finds the next occurrence of the same month and day. Leap year count uses the rule: divisible by 4, except century years which must be divisible by 400.
Frequently Asked Questions
How do I calculate my age in days?
Subtract your birth date from today's date. This calculator shows your exact total day count automatically. For a rough estimate: multiply your age in years by 365 and add the days since your last birthday.
How old am I if I was born in 1990?
If you were born in 1990, you are 34 or 35 years old in 2025, depending on whether your birthday has passed this year. Enter your exact birth date above for a precise answer including months and days.
What day of the week was I born?
Enter your date of birth in this calculator and scroll down to the fun facts section. It shows the exact day of the week you were born using the JavaScript Date API, which correctly handles the Gregorian calendar for all dates since 1582.
How many days until my birthday?
This calculator shows a birthday countdown after you enter your date of birth. It finds the next occurrence of your birth month and day, whether that is this calendar year or next year, and shows the number of days remaining.
How do I calculate age between two dates?
Use the "Custom date" toggle in the "As of" field. Enter your birth date, then enter any target date. The calculator shows your age at that specific date, useful for historical records or future planning.