How do I use the age calculator?
- Enter the date of birth.
- Check the “age on” date. It starts as today's date; change it to find an age on any other day.
- Read the age in years, months and days, the totals in months, weeks and days, the weekday you were born and the date of your next birthday.
How is exact age calculated?
Age in years is the number of birthdays that have passed. The months are the full months since the last birthday, and the days are what remains since the last monthly anniversary of the birth date. When that anniversary falls on a day the month doesn't have, such as the 31st in a 30-day month, the last day of the month is used. This matches how age is normally counted in everyday life and for official forms.
Total days are an exact count of calendar days, including every February 29, so they are useful for things like counting a 10,000th day. Hours and time zones are ignored: the calculator uses calendar dates only.
Worked examples
Example 1: exact age on a date
Born Friday, June 15, 1990. On November 3, 2026 the age is 36 years, 4 months and 19 days: 436 months, 1,898 weeks or 13,290 days in total. The next birthday, Tuesday, June 15, 2027, is 224 days away.
Example 2: a leap-day birthday
Born February 29, 2000. In common years the calculator treats February 28 as the birthday, so on February 28, 2026 the age is 26, and on March 1, 2026 it is 26 years and 1 day. The next real February 29 birthday is in 2028.
Example 3: retirement age check
Born November 3, 1958. On November 3, 2026 the age is exactly 68 years. The full retirement age set by Social Security for people born in 1958 is 66 and 8 months, which that person passed in July 2025.
Where do people need an exact age?
- School entry and sports: age on a cut-off date such as September 1 or January 1.
- Benefits and retirement: Social Security, Medicare at 65 and required minimum distributions depend on exact age.
- Medical and developmental checks: a child's age in months, or chronological age in years, months and days for assessments.
- Work: minimum ages under child labor rules and length of service. For tenure between two dates, use the date calculator.
To count down to a birthday, try the days until calculator, or find the weekday you were born with the day of the week calculator.