Birthday-first calculation
Completed birthdays determine the year count before complete months and remaining days are measured. Someone born May 20, 1990 is 35 on May 19, 2026 and turns 36 on May 20.
Age calculator
Find an exact age in calendar years, months, and days, plus lifetime days and the countdown to the next birthday.
30 years, 0 months, 0 days
Born on Wednesday, October 2, 1996, a Wednesday.
Total days10,957
Next birthdayOct 2, 2026
Birthday countdownToday
Calendar age advances by anniversaries first, then complete months, then remaining days. A February 29 birthday uses February 28 as its anniversary in non-leap years.
How it works
Calendar age, not an average
Exact calendar units
Years and months follow real anniversary dates rather than average month or year lengths. The displayed years, months, and days therefore describe a calendar age, not a decimal-age estimate.
Leap-day birthdays
This calculator treats February 28 as the anniversary of a February 29 birthday in non-leap years. Legal and administrative rules can vary by jurisdiction, so verify the applicable rule for official deadlines.
Total days lived
The total-days metric is the elapsed calendar-day distance from the birth date to the as-of date: the birth date is day zero. Use days between dates to include both endpoints instead.
Age on another date
Choose a past or future as-of date to check age at a graduation, retirement date, eligibility deadline, or other milestone. The next-birthday countdown is calculated from that same as-of date.
Plan from a birthday
Both inputs stay in the URL for bookmarking or sharing. To move a birth or milestone date by a fixed duration, use the add-or-subtract date calculator.