Exactly how old are you?
Enter your birth date to calculate your exact age in years, months and days—plus total days lived, your birth weekday, and your next birthday countdown.
Calculate your age
More than a birthday calculator
CalculateAge.us handles calendar dates correctly instead of estimating age from an average year length.
Exact age
See years, months, and days using real calendar boundaries.
Total time lived
View full months, full weeks, and total calendar days.
Any target date
Change “Calculate age on” to see how old someone was—or will be—on another date.
Age difference calculator
Compare two birth dates and see the exact difference between them.
Age calculator FAQ
How is exact age calculated?
The calculator counts complete calendar years, then complete calendar months, then the remaining days between the birth date and the selected calculation date.
Does the calculator work for leap-day birthdays?
Yes. February 29 birthdays are handled using the real Gregorian calendar. The next-birthday countdown uses February 28 in non-leap years.
Can I calculate age on a past or future date?
Yes. Change the “Calculate age on” field to any date on or after the birth date.
Is my birth date stored?
No. The calculations run in your browser and this page does not need to send your birth date to a server.