How to Calculate Your Age

An age calculator finds your exact age by measuring the difference between your date of birth and today's date (or any target date). The result is expressed in years, months, and remaining days — the most natural way people think about age.

The Age Formula

Age calculation seems simple but has important edge cases around month lengths and leap years. The standard approach:

A more accurate method counts calendar months directly, adjusting for whether the birth day has passed in the current month.

Why Does Age Calculation Get Complex?

Different months have 28, 29, 30, or 31 days. Leap years add an extra day every 4 years (with century exceptions). This means the gap between two dates isn't always a clean multiple of any fixed period. Our calculator handles all edge cases including February 29 birthdays.

Age in Different Cultures

In most Western countries, age increases on the anniversary of your birth. In South Korea, everyone turns one year older on January 1st, and babies start at age 1. In East Asian traditional reckoning, a newborn is already "one year old." Our calculator uses the international standard (Western) method.

How to Use This Calculator

Simply enter your date of birth using the date picker above. The calculator will instantly show your age in years, months, and days, plus your total age in weeks, days, hours, minutes, and seconds. You can also select a custom "age as of" date to calculate your age on a specific past or future date.