Age Calculator
Find your exact age in years, months, and days — plus a countdown to your next birthday.
About Age Calculator
Age Calculator works out an exact age from a birth date — broken into years, months, and days, plus totals in days, weeks, hours, minutes, and seconds. It also computes the number of days to the next birthday and what day of the week that birthday falls on. The use cases range from a casual 'how old am I in days' to working out a precise age at a particular event (an exam date, a milestone, an insurance application).
Worked example: born 1990-03-15, on 2026-05-23 you are exactly 36 years, 2 months, and 8 days old — equivalent to about 13,219 days, 1,888 weeks, or 317,256 hours. The next birthday is 2027-03-15, in 296 days. By default the calculator uses today's date; switch the 'as of' date to compute age at any moment, useful for working out how old someone was at a past event or will be at a future one.
Two notes. Month and day differences are computed on the actual calendar, so leap years and the different month lengths are handled correctly — a birth on 1990-02-28 and a birth on 1990-03-01 produce noticeably different ages at the end of February in a non-leap year. The day-of-week your next birthday falls on is computed deterministically, and the calculator also shows the day of the week you were born — a popular trivia question. The 'as of' field accepts any date, including future ones, which is useful for legal-age and milestone calculations.
All calculation runs entirely in your browser. Birth dates and personal milestone dates never leave your device.