How does the age calculator handle leap years?

The calculator correctly accounts for leap years (years divisible by 4, with century-year exceptions). A leap year has 366 days, which affects the day count for anyone born on or after February 29.

What if I was born on February 29 (leap day)?

Leap day birthdays are handled correctly. In non-leap years, your birthday is considered to fall on February 28 or March 1 depending on convention. Our calculator uses February 28.

Can I calculate the age between two custom dates?

Yes! You can change both the "Date of Birth" and "As of Date" fields to calculate the time between any two dates — not just from birth to today.

How is age calculated officially?

In most countries, age is calculated by counting completed years from birth to the current date. If your birthday hasn't occurred yet this year, you are still the age you turned on your last birthday.

What day of the week was I born on?

The calculator shows the day of the week for your date of birth using the Zeller's congruence algorithm, which is accurate for any date from 1582 onward (Gregorian calendar).

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Age Calculator

Calculate your exact age in years, months, days and hours from date of birth.

Date of Birth

Age As Of

How to Use Age Calculator

1
Enter your date of birth using the date picker.
2
The "As of date" defaults to today — change it for historical calculations.
3
Click "Calculate Age" to see your exact age.
4
View your age in years, months, days, hours, and minutes.
5
Check the countdown to your next birthday and the day you were born.

About Age Calculator

Our Age Calculator gives you your exact age down to the day — no more guessing. Enter your date of birth and today's date, and instantly see your age in years, months, days, hours, minutes, and seconds. You'll also see how many days until your next birthday and what day of the week you were born on.

This tool is used by millions of people for a wide range of purposes: filling out official forms, verifying age eligibility, calculating retirement milestones, preparing for birthdays, or simply satisfying curiosity. It correctly handles leap years, so your birthday calculations are always accurate.

You can also calculate the age of anything — a car, a company, a tree — by entering any two dates. The tool shows the time difference in multiple units simultaneously, making it versatile for any date-based calculation.