Age Calculator

The Age Calculator computes your exact age in years, months and days from your date of birth. It also shows the total number of days, weeks and months you have lived, and counts down to your next birthday — handy for planning celebrations or just satisfying curiosity.

Age calculation sounds simple but is surprisingly fiddly to do by hand because calendar months have different lengths (28 to 31 days) and leap years add an extra day every four years. A correct age calculator must account for these irregularities. This tool uses date arithmetic that respects month boundaries: if you were born on January 31, the calculator will not pretend 'one month later' is February 31 — it correctly handles the shorter month.

Beyond simple curiosity, exact age matters in many practical contexts: verifying eligibility for age-restricted services, filling out forms that require age in years and months (such as school enrollment, insurance, and immigration paperwork), calculating age for medical dosing in pediatrics, and tracking milestones. The total-days-lived figure is popular for novelty ('I have been alive for 12,345 days!') but also useful for calculating elapsed time in scientific and contractual contexts.

The next-birthday countdown tells you exactly how many days remain until your next birthday, so you never miss a planning window. Everything runs locally in your browser; your date of birth is not stored or transmitted.