Age Calculator

Age is calculated by comparing the birth date to today. Years are counted as full years since birth. Remaining months and days are computed by subtracting month and day values, borrowing from the previous month when the current day is less than the birth day.

Leap years occur every 4 years, except for years divisible by 100 (unless also divisible by 400). If you were born on February 29, your birthday technically occurs once every 4 years. The calculator handles this correctly by using the native Date API which accounts for leap years.

In most Western countries, age starts at 0 at birth. In East Asian age reckoning (used traditionally in Korea, China, Japan), a baby is considered 1 year old at birth and gains a year every New Year. This calculator uses the Western system.

Western zodiac signs are determined by birth date ranges: Aries (Mar 21-Apr 19), Taurus (Apr 20-May 20), Gemini (May 21-Jun 20), Cancer (Jun 21-Jul 22), Leo (Jul 23-Aug 22), Virgo (Aug 23-Sep 22), Libra (Sep 23-Oct 22), Scorpio (Oct 23-Nov 21), Sagittarius (Nov 22-Dec 21), Capricorn (Dec 22-Jan 19), Aquarius (Jan 20-Feb 18), Pisces (Feb 19-Mar 20).

Legal ages vary by country: voting age is typically 18, drinking age is 18-21, driving age is 15-18, age of majority is 18 in most countries. In the US, you can vote at 18, drink at 21, and run for president at 35.