How to use
- Enter your date of birth.
- Leave the second date as today, or choose a past or future date.
- Select "Calculate age" to see your age and birthday countdown.
How age is calculated
The tool counts whole calendar months from your date of birth, using the last day of a month when the same day does not exist. Each 12 months counts as a year. Whatever is left over is shown as days.
Total days lived is the number of days from your date of birth to the calculation date. The day you were born counts as day 0. For example, someone born on October 10, 2000 is 26 years old on October 10, 2026.
February 29 birthdays
In a year without February 29, this birthday calculator uses February 28 for both completed age and the next birthday. That's just how this tool counts. Rules for leap-day birthdays vary, so if your exact age matters for something official, check with the organization involved.
Dates you can use
Dates must be in the years 1000 through 9999. The calculation date can be in the future, but it cannot be earlier than the date of birth. A birthday on the calculation date has a countdown of 0 days.
To compare other dates or add time to a date, use the date calculator.
Frequently asked questions
Can I calculate my age on a future date?
Yes. Change "Calculate age on" to the date you want. The calculation date must be on or after your date of birth.
When does a February 29 birthday fall in a non-leap year?
This tool uses February 28. That rule applies to the age calculation and the birthday countdown; an organization may use a different rule.
Why isn't a month counted as 30 days?
Months follow the calendar and have different lengths. The tool counts whole months first, then the remaining days.
Is my birthday saved?
Your dates are processed in your browser and are not saved by this calculator. The page itself uses Google Analytics and shows ads.