🎂 Age Calculator
How old am I exactly?

Age Calculator — How Old Am I Exactly?

Enter your birthday to see your precise age in years, months, days, hours, and minutes.

Your birth date stays on your device.

How Age Is Calculated

Exact age calculation works by counting complete years first, then complete months within the remaining period, then remaining days — always accounting for leap years and variable month lengths.

The Algorithm

Starting from the birth date, the calculator advances by one year at a time until the next year would exceed today. Then it advances one month at a time. Any remaining days are counted separately. This ensures February birthdays, leap years, and month-end dates (like Jan 31 → Feb 28/29) are always handled correctly.

Leap Day Birthdays (Feb 29)

If you were born on February 29, your official birthday in non-leap years is treated as March 1. The next-birthday countdown reflects this: in a non-leap year it counts down to March 1; in a leap year to February 29.

Planetary Ages

To find your age on another planet, divide your total age in Earth days by that planet's orbital period. Mercury's year is 87.97 Earth days, so a 30-year-old is about 124.5 Mercury years old. Jupiter's year is 4,332.6 Earth days, making the same person just 2.5 Jupiter years old.

Frequently Asked Questions

Age is calculated by subtracting the birth date from today. Years are counted first, then remaining months, then remaining days — accounting for leap years and varying month lengths. For example, someone born January 31 whose next month-end falls on February 28 is counted as 0 extra days until March 1.
Total days alive = (today − birth date) in milliseconds ÷ 86,400,000. This counts every calendar day including leap days. The calculator shows this in the detailed breakdown.
Planetary age = your Earth-days age ÷ planet's orbital period in Earth days. Mercury = 87.97 days, Venus = 224.7, Mars = 686.98, Jupiter = 4,332.6, Saturn = 10,759. A 30-year-old has been alive ~10,957 Earth days = ~124.6 Mercury years or ~2.53 Jupiter years.
Western zodiac signs are based on birth month and day. 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.
For leap-day birthdays, the next birthday is February 29 in leap years and March 1 in non-leap years. Age counting is still accurate — a full year passes between each birthday regardless.
No. All calculations run in your browser. Your birth date is stored only in your own browser's localStorage for convenience. It never leaves your device.