Age Calculator

Calculate exact age from a birth date, accounting for the calendar — leap years and month lengths are handled so the result is correct even for birthdays on the 29th, 30th, or 31st. Shows age in years, months, and days; total days and weeks lived; the weekday you were born on; and a countdown to your next birthday. "Today" defaults to the current date in UTC and you can edit it to compute an age as of any date. Everything runs locally in your browser.