Age Calculator
Enter your date of birth and get your exact age — down to the second — along with how many days are left until your next birthday.
What your exact age really tells you
We usually round our age to a whole number of years, but a birthday is only one slice of a much richer story. This calculator takes your date of birth and works out the precise distance to today, then expresses it several ways at once: complete years, months and days for everyday use, and the grand totals of days, hours and seconds for the moments when you want to feel the full sweep of time you have lived. Switch on the live counter and you can watch the seconds tick upward in real time, a quietly mesmerising reminder that age is something you are always accumulating, not just on one date a year.
Why the maths is trickier than it looks
Calculating an age sounds like simple subtraction, but the details bite. Months are different lengths, leap years slip an extra day into February every four years with their own exceptions, and the day of the month you were born on shifts the count. A naive calculation can easily be a day or two out. This tool borrows days from the previous month exactly the way a careful person would, so the years-months-days figure is genuinely correct rather than an approximation. It also looks ahead to the next time your birth date comes around and counts the days until then, which is useful whether you are planning a celebration, booking time off, or arranging a surprise.
More than just your own birthday
The calculator works for any date, not only your own. Enter a child's birthday to see their age in days for a baby book, a parent's or grandparent's to prepare for a milestone, or a wedding date to count an anniversary. You can also set the "calculate age on" field to a future or past date to see how old someone was, or will be, on a particular day. Because everything is computed inside your browser, the dates you enter stay on your device and are never sent anywhere. When you want to look forward to the next milestone rather than measure the one behind you, pair this with the countdown timer, and use the date-difference tool to measure spans that do not start from a birthday.