Updated October 9, 2026
Age Calculator
Enter your date of birth and get your exact age in years, months and days, your total days and weeks alive, the day of the week you were born, and a live countdown to your next birthday.
What this tool does
The age calculator turns a birthdate into a full picture: your age in calendar years, months and days, your total days and weeks alive, the weekday of your birth, and how many days remain until your next birthday (plus which weekday it falls on and which age you turn).
How the age math works
Years, months and days are computed with the borrowing method you would use by hand. Subtract the birth year, month and day from today's year, month and day; if the day difference is negative, borrow one month (adding that month's actual length in days); if the month difference is negative, borrow one year. This respects real calendar months, including February in leap years.
Worked example
Born 1990-06-15, on 2026-10-09 you are 36 years, 3 months and 24 days old. The day difference (9 minus 15) is negative, so one month is borrowed: September has 30 days, giving 9 + 30 - 15 = 24 days, and the month count drops by one. Total days lived: 13,265.
Leap day birthdays
If you were born on February 29, the next-birthday countdown targets February 29 in leap years and February 28 otherwise, which matches how most legal systems treat the birthday in common years.
Limitations
Ages are computed in your device's local time zone, so the exact day boundary follows your clock. The tool counts whole days only; hours and minutes are not shown.
Planning estimate only. Results use the list prices shown and may differ from your actual bill. Terms
Frequently asked questions
How is age in years, months and days calculated?
By calendar borrowing: subtract the birth date from today, borrowing days from the previous month when the day difference is negative and a year when the month difference is negative. Months keep their real lengths, so leap years are handled correctly.
What day of the week was I born?
Enter your birthdate above and the note under the results shows the weekday you were born on, along with the full date.
How many days until my next birthday?
The calculator shows the days remaining until your next birthday, which weekday it falls on, and the age you will turn. For February 29 birthdays it uses February 28 in non-leap years.
Why does another site show a slightly different age?
Most differences come from time zones or from counting the current day differently. This tool uses your device's local date at whole-day precision, which matches how birthdays are celebrated.
Is my birthdate sent anywhere?
No. The calculation runs entirely in your browser. Your birthdate is never uploaded, stored or shared.