Find your exact age in years, months, and days — or the age between any two dates — plus your next birthday countdown.
Enter the dates
How age is calculated
Age in years, months, and days is found by comparing two calendar dates directly — not just dividing total days by 365, since months and years vary in length. This calculator counts whole years first, then whole months within the current year, then remaining days, so leap years and different month lengths don’t throw off the result.
Why total days can matter too
Some milestones — like a “10,000 days old” celebration, or matching an age requirement measured in days rather than years — need the exact day count rather than a years/months/days breakdown. This calculator shows both.
Frequently asked questions
Can I calculate age as of a past or future date, not just today?
Yes — change the “calculate age as of” field to any date, past or future, to find someone’s age at a specific event, or how old they’ll be on a future date.
Why does the month count sometimes look off by one?
If the day-of-month of the birth date hasn’t occurred yet in the current month, that month doesn’t count as a full month — the calculator borrows days from the previous month, the same way you’d count it by hand on a calendar.
Does this account for leap years?
Yes — the calculation works directly with calendar dates, so leap years (and their extra day in February) are handled automatically.