Days Until Birthday Calculator
Want to know exactly how many days until your next birthday, and what age you will turn? Enter your date of birth and this calculator finds the countdown, the day of the week it falls on, and the age you are about to reach.
How the countdown is calculated
The calculator applies your month and day to the current year. If that date has already passed, it rolls forward to next year instead, so the countdown always points at the next real occurrence rather than the one that already happened.
A birthday on February 29 only exists once every four years. In a year that is not a leap year, this calculator treats February 28 as the occurrence, matching the convention used across the rest of this site: contracts, subscriptions, and most calendar software resolve a missing date the same way.
Example
Someone born on 8 November checking the calculator on 24 September is 45 days from their next birthday. If they check again on 10 December, the same date of birth now points to next year's occurrence instead, because this year's has already gone by.