Birthday Countdown Calculator — Days Until Next Age

This calculator works out the exact time remaining until your next birthday and displays it as a live ticker — days, hours, minutes, and seconds — that ticks down in real time in your browser. There is no page refresh or server involved once your date of birth is entered; the seconds update every second using your device's clock.

If your birthday has already occurred this calendar year, the calculator automatically counts forward to the same date next year. You never have to think about whether your birthday is “upcoming” or “past” — it always shows the next one. For February 29 birthdays in non-leap years, the countdown targets the last day of February.

Below the live countdown you'll find a shareable summary card with your days remaining, the day of the week your birthday falls on, and the age you'll be turning — plus a table of upcoming milestone birthdays like 21, 30, and 10,000 days old, filtered to show only future dates.