Enter a birth date to calculate exact age, total months, and days until the next birthday.
Age Calculator
Actual age counts completed years from birth — you gain one year on each birthday, which is the legal and international standard. Nominal age (虚岁) is a Chinese tradition: you start at age 1 at birth and gain one year each Lunar New Year, usually 1-2 years higher than actual age.
Subtract the start date from the end date to get the number of days. This age calculator can also be used for project timelines and countdowns. For more complex date calculations (e.g., working days), try our Date Calculator tool.
Common age group classifications: Infant (0-1), Toddler (1-3), Preschool (3-6), Child (6-12), Adolescent (12-18), Young Adult (18-45), Middle-aged (45-60), Senior (60+).