The basic method
Subtract the birth year from the current year. If your birthday has not happened yet this year, subtract one more. Someone born on November 20, 2000 is 25 on October 12, 2026, and turns 26 on November 20. Our age calculator gives the exact result instantly.
Years, months and days
For an exact breakdown, count full years first, then full months since the last birthday, then the remaining days. For a birth date of March 15, 1990, on October 12, 2026 the age is 36 years, 6 months and 27 days. Month lengths differ, which is why calculators are more reliable than mental math here.
Age in days or weeks
To find age in days, count the days between the two dates, including leap days. A 30-year-old has lived about 10,957 days. Our days between dates calculator does this, and dividing by 7 gives weeks. Many people celebrate their 10,000th day, which falls at about 27 years and 5 months.
Leap-year birthdays
People born on February 29 have a birthday only every four years. In non-leap years, legal age is generally recognized on February 28 or March 1 depending on the country. For everyday celebrations, either date is common.
Different age systems
In some cultures age was traditionally counted differently; for example, South Korea used a system where babies were one year old at birth until it standardized on international age for official purposes in 2023. Always use international age for official forms.
Common uses
Exact age matters for school enrollment cut-off dates, retirement and pension eligibility, insurance quotes, sports age groups and visa applications. Many school systems use a specific cut-off date such as September 1, so a child's age on that date decides the grade.
Age milestones
Popular milestones include 18 and 21 (legal adulthood in many places), 50, and retirement ages. Countdown to a milestone birthday with our days between dates tool.
Time zones
If you were born just before midnight, the date in another time zone may differ, but legal age always uses the date on your birth certificate.
Frequently asked questions
How do I calculate my exact age?
Subtract birth year from the current year and subtract one more if your birthday hasn't occurred yet this year.
How old is someone born in 2000 in 2026?
25 or 26, depending on whether their birthday has passed.
When is my 10,000th day?
At about 27 years and 5 months old.
When do people born on February 29 celebrate?
Usually on February 28 or March 1 in non-leap years.