Age Calculator

Enter your birth date to find your exact age, total days alive, next birthday countdown, and more.

Your Age

Years, months, and days

Total Days Alive

Including leap days

Next Birthday

Days until your next birthday

Day of the Week

The day you were born

Zodiac Sign

Western astrology

Age Facts & Milestones

Leap Year Rules

A year is a leap year if it is divisible by 4, except for century years (divisible by 100), which must also be divisible by 400. So 2000 was a leap year, but 1900 was not. This means a leap year occurs roughly every 4 years, adding February 29 to the calendar.

  • Divisible by 4: Leap year (2024, 2028, 2032)
  • Divisible by 100: Not a leap year (1900, 2100)
  • Divisible by 400: Leap year (2000, 2400)

Fun Age Facts

  • The average human heart beats about 100,000 times per day — roughly 36.5 million times per year.
  • By age 30, you have spent about 10 years sleeping.
  • A billion seconds is approximately 31.7 years.
  • If born on February 29, you only celebrate your "real" birthday once every 4 years.

Common Age Milestones

Age Milestone (US)
16 Can drive in most states
18 Legal adult, can vote
21 Legal drinking age
25 Car insurance rates drop
62 Early Social Security
65 Medicare eligibility

Note: All calculations are performed in your browser. No personal data is stored or transmitted.

Frequently Asked Questions

How does this age calculator handle leap years?
The calculator uses JavaScript Date objects, which correctly handle leap years. February 29 birthdays are recognized, and the calculator accounts for the extra day every four years (with exceptions for century years not divisible by 400). Your age in days will accurately reflect all leap days that occurred during your lifetime.
Why does my age in months not match a simple subtraction?
Months have different lengths (28, 29, 30, or 31 days), so simple month subtraction can be off. This calculator counts complete calendar months by comparing the day of the month. If you were born on the 31st and the current month has only 30 days, the calculation adjusts accordingly to give an accurate result.
What is the zodiac sign based on?
The zodiac sign shown is based on Western (tropical) astrology, which divides the year into 12 signs based on the position of the sun relative to constellations at the time of your birth. The date ranges used are the traditional ones recognized in Western astrology. Vedic (sidereal) astrology uses different dates.
Can I use this calculator for dates far in the past?
The calculator works with any date supported by your browser, which typically covers years from 1 to 9999. However, for very old dates, keep in mind that calendar reforms (such as the switch from Julian to Gregorian in 1582) are not accounted for. The calculator uses the proleptic Gregorian calendar throughout.

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