Date & Time Live Counter

Age Calculator

Enter your date of birth to get your exact age in years, months, days, hours and seconds - with a live countdown to your next birthday.

Date of Birth

Age Milestones

First steps	~1 yr
Legal adult	18 yrs
No car hire surcharge	25 yrs
Early SS retirement (US)	62 yrs
Full retirement (US)	67 yrs
Centenarian	100 yrs

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Enter your date of birth to get started

How Age is Calculated

Age is calculated from the exact millisecond difference between your date of birth and the current date, accounting for varying month lengths and leap years. If you were born on 29 February, your age increments on 28 February in non-leap years.

Age Systems Around the World

System	Rule
Western (standard)	Age starts at 0 at birth, increments on each birthday
East Asian traditional	Born at age 1, increments each Lunar New Year
Islamic calendar	Uses Hijri lunar calendar (~354 days/year)

Frequently Asked Questions

How many days have I been alive?

Enter your date of birth above. As a rough estimate: a 30-year-old has lived ~10,950 days; a 40-year-old ~14,610 days.

Does the counter update automatically?

Yes - the birthday countdown and the total seconds counter both update every second in your browser. No page refresh needed.

Can I calculate someone else's age?

Yes. Enter any past date of birth and the calculator returns the exact age and next birthday countdown for that person.