The calculator computes your exact age in years, months, and days by accounting for the varying number of days in each month and leap years. It correctly handles edge cases such as birthdays on February 29 and month-end date differences, giving you a precise result down to the day.
By default the reference date is today's date. You can change it to any date in the past or future to calculate how old you were or will be on a specific day — useful for legal age verification, anniversary planning, or historical research.
The birthday countdown shows how many days remain until your next birthday from the reference date. If your birthday has already passed this year, it counts toward the following year. This makes it easy to plan surprise parties, gifts, or simply keep track of the special day.