Find your exact age in years, months, and days — plus your total days lived and your next birthday.
This tool counts the full years, then the remaining months, then the remaining days between your date of birth and a chosen date (today by default). It accounts for the different number of days in each month and for leap years.
It's tempting to find someone's age by subtracting their birth year from the current year, but that's often off by a year. If you were born in December 1990, in June 2026 you are 35, not 36, because your birthday for 2026 hasn't happened yet. An accurate age calculation has to compare the full date — day, month, and year — not just the year. This calculator does exactly that, checking whether the month and day have passed to give you the correct number of completed years, months, and days.
Leap years add a 29th of February every four years to keep the calendar aligned with Earth's orbit. This matters for precise day counts: across several years, leap days accumulate, so a simple "× 365" estimate of your age in days will drift. Our calculator counts the actual number of calendar days between the two dates, so leap years are handled automatically. People born on February 29 — "leaplings" — technically only have a calendar birthday every four years, though for legal purposes their birthday is usually treated as February 28 or March 1 in non-leap years.
The number this tool gives you is your chronological age — the exact time elapsed since birth. It's the figure used for legal milestones, eligibility, and official forms. It differs from concepts like biological age (an estimate of how aged your body is based on health markers) or the East Asian "age reckoning" system, in which a person is considered one year old at birth. For nearly all everyday and official purposes, chronological age is what you need.
Enter your date of birth and the date you want to measure to (today is filled in by default). The calculator counts the completed years, then the remaining months, then the remaining days between the two dates, accounting for leap years and the different lengths of each month.
The calculator shows your total age in days automatically — it counts every calendar day between your birth date and the target date, including leap days, rather than estimating with a fixed 365-day year.
Yes. Change the "Age at Date" field to any past date and the calculator will show how old you were on that day. You can also set it to a future date to see how old you'll be then.
It compares the actual calendar dates, so leap years and February 29 are accounted for automatically. The total-days figure reflects the real number of days elapsed, not an approximation.
Chronological age — what this tool calculates — is simply the time that has passed since you were born. Biological age is a health-based estimate of how "aged" your body is, which can be higher or lower than your chronological age depending on lifestyle and genetics.