Age Calculator

Calculating age sounds trivial, but doing it precisely requires care. Your age in years is the number of complete years since your birth date. The remaining months are the complete calendar months since your last birthday, and the remaining days count from the same day of the most recent month. The tricky part is that months have different lengths (28 to 31 days) and leap years add an extra day to February roughly every four years. This calculator handles all of these edge cases using calendar-accurate date arithmetic, so someone born on 31 January still gets a correct answer at the end of February.

The total days lived figure is a simple difference between today and your birth date, which automatically includes every leap day along the way. It is a fun number to know — 10,000 days falls a few months after your 27th birthday, and 20,000 days arrives in your mid-fifties.

Exact age matters in more situations than you might expect. Official forms and applications — competitive exams, government job applications, and visa forms often require your age in completed years, months, and days on a specific cut-off date. School admissions commonly have minimum-age rules measured to the day. Insurance and pensions use age at entry to determine premiums and eligibility. And of course, it settles friendly debates about exactly how much older one sibling is than another.

Because this tool runs entirely in your browser, your date of birth is never transmitted or stored anywhere — the calculation happens on your own device.