Age calculator

The algorithm starts from the date of birth and advances toward the reference date (today by default). It first counts the complete years elapsed: a year is considered complete once the birthday month and day have already passed in the current year. It then counts the remaining complete months in the same way, taking into account that months have different lengths. Whatever is left after the complete months is expressed in days. The final result is something like "32 years, 4 months and 17 days" — a more precise representation than simply "32 years".

The reference date lets you calculate age at a point in time other than today. This has very practical uses: you can find out how old you were on an important historical date, calculate what age you will be when you retire or when a specific deadline arrives, verify whether someone was of legal age on a particular date, or simply explore with curiosity how old you were when a memorable event took place. The reference defaults to the current date, but you can freely change it to any past or future date.

The logic takes the birth day and month and combines them with the current year. If that date has already passed this year, the next birthday falls in the following year. If it has not yet occurred, it falls in the current year. A special case is February 29: people born on a leap day celebrate their birthday on February 28 in non-leap years, following the most widely used convention. The result tells you how many days remain until your next birthday and which age you will turn.

Because each year has 365 days (or 366 in a leap year) and those add up fast. By age 20 you have already lived around 7,300 days; by 30, approximately 10,950; by 40, close to 14,600. It is a number that often surprises people, since we are used to thinking of age in years. Seeing the figure in days is useful, for example, to calculate cumulative totals, plan long-term goals, or simply gain a different perspective on the time you have lived.

Human Resources professionals use it to verify whether a candidate meets minimum age requirements, calculate when someone reaches retirement age, or determine exact seniority within a company. Lawyers and notaries consult it to confirm legal adulthood on a specific date, calculate ages in civil litigation, or verify timelines in inheritance and guardianship cases. Doctors and paediatricians use it to convert a patient's age into exact months and adjust paediatric drug doses with precision. Insurance and finance professionals rely on exact age to calculate actuarial premiums, retirement eligibility, and qualification for age-restricted financial products. Parents and educators use it to determine whether a child meets the minimum age cut-off for enrolling in a course, sport, or programme.

On desktop, press Ctrl + D (Windows/Linux) or Cmd + D (Mac) in Chrome, Firefox, or Edge to add this page to your bookmarks instantly. In Safari for Mac, use Cmd + D or go to Bookmarks → Add Bookmark. On mobile with Chrome (Android), tap the three-dot menu (⋮) and choose "Add to Home screen" or "Add to bookmarks." On mobile with Safari (iPhone/iPad), tap the share button (□↑) and then "Add to Home Screen." Once on your home screen it works like an app — one tap to open whenever you need to verify an age quickly.