Age
This age calculator turns a single date of birth into your exact age today: the full years you have lived, plus the leftover months and days. It also adds up the total number of days you have been alive and counts down to your next birthday, so you get the round-number milestones as well as the everyday detail. Every figure recalculates the moment you change the date.
The calculator compares your date of birth with today using real calendar dates, not a flat 30-day month. It first counts the whole years between the two dates, then the whole months left over, then the remaining days. Counting in that order is what people mean by "exact age": you are 26 only once the day and month of your birthday have both come around again, not the moment the year number changes.
Because the leftover days are measured against the real length of each month, a month-end birth date still lands correctly. Someone born on December 31, 1990 is, on June 30, 2026, exactly 35 years, 5 months, and 30 days old, even though the months in between range from 28 to 31 days long. There is no rounding step in the middle that could drift over a long span.
The total-days figure is a separate, straight count from your birth date to today, every leap day included. For the December 31, 1990 example above, that is 12,965 days. People reach for this number to plan a "10,000 days alive" celebration (about 27 years and 4 months), to compare two ages precisely, or simply because a days count feels more concrete than a years-and-months breakdown. It is the same arithmetic a hospital or a court would use, so it matches official day-count math rather than an estimate.
Leap days are counted automatically, because the math runs on real calendar dates rather than an assumed 365-day year. The one case that trips people up is a February 29 birthday in a year that has no February 29. This calculator treats March 1 as the day you turn a year older in those years. So someone born on February 29, 2000 reads as 25 years, 11 months, and 30 days on February 28, 2026, and ticks over to a full 26 years on March 1, 2026 — the same convention used for legal age in many places. The next-birthday countdown follows the same rule, pointing at the real February 29 whenever the upcoming year is a leap year.
The number this tool shows is your "Western" or international age: you start at 0 at birth and gain a year on each birthday. Traditional Korean age counts differently — a baby is 1 at birth and everyone adds a year at the New Year — which left people one or two years "older" than their birthday age. South Korea standardised on the international system in June 2023, so the figure here now matches the official age used on Korean documents too. If you still want the traditional count, add roughly one to two years depending on how far into the year your birthday falls.
How is my exact age worked out?
It counts the full years from your birth date to today, then the leftover months, then the leftover days. So someone born on January 1, 2000 is 26 years, 5 months, and 27 days old on June 28, 2026.
What does "total days" mean?
It is the plain count of days you have been alive, from your birth date up to today, leap days included. It is a single number rather than a years-and-months breakdown.
How are leap years handled?
They are counted automatically. Because the calculation uses real calendar dates, February 29 and the extra day in leap years are already included in both your age and your total days.
What if I enter a date in the future?
You can't have an age before you're born, so the calculator simply tells you the date is in the future instead of showing a negative number. Pick a date of birth on or before today.
When does the next birthday countdown reset?
On the day itself it shows zero, and the day after it counts down to the same date next year. It always points at the next time your birth month and day come around.
Last reviewed June 2026.