Age Calculator

Enter a date of birth and get an exact age broken down into years, months, and days, plus total days lived.

Age seems like it should be the simplest possible calculation — subtract a birth year from the current year — but the moment you want precision down to the day rather than just the year, it stops being simple arithmetic and starts requiring actual calendar logic: months have different lengths, leap years add an extra day roughly every four years, and whether someone has technically "turned" their next age depends on whether their birthday this year has already passed, which is exactly the kind of detail that's easy to get wrong doing it by hand.

That precision matters more than it might seem for certain uses — legal age thresholds, eligibility cutoffs, and some medical or developmental milestones are defined in exact years and sometimes months, not "approximately." A calculator that gets the leap-year and month-length edge cases right removes a category of small errors that manual counting on fingers or a mental calendar tends to introduce.

This tool takes a birth date and calculates the exact current age in years, months, and days, along with the same figure expressed in total days, weeks, hours, minutes, and seconds lived — since sometimes the more dramatic framing (measured in total hours, for instance) is exactly what someone's actually looking for rather than the plain years-and-months figure.

1. Enter your (or someone else's) date of birth.
2. Press "Calculate age."
3. See the exact age and total number of days lived.