How is exact age calculated?

The calculator finds the difference between your date of birth and today in complete years, then counts the remaining months and days. Leap years and months of different lengths are all handled correctly.

Is this age calculator free?

Yes, completely free. No account, no sign-up, and no data is ever sent to our servers.

Do I need to create an account?

No. The tool runs entirely in your browser. Enter your date of birth and the results appear instantly.

Age calculator

Age calculator is a date tool that computes your exact age in years, months, and days from your date of birth. It shows total days lived, your age in hours, your next birthday with a countdown, and the day of the week you were born. The tool runs in your browser.

Date of birth

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Dedicated age calculators

Focused pages for specific age calculation needs.

Age in Days Calculator

Calculate your exact age in days, hours, and minutes from your date of birth. Free, instant, runs entirely in your browser.

Age Calculator from Birthday

Calculate your exact age from your birthday. See your age in years, months, and days, plus your next birthday date. Free, private, in-browser.

Days Until Birthday Calculator

Find out how many days until your next birthday. Enter your date of birth for an instant countdown. Free, private, runs in your browser.

How to calculate your age

Enter your date of birth in the date field.
Your exact age in years, months, and days appears immediately.
Switch between views using the panel: Years & months, Total days, or Birthday countdown.
Scroll down to see all details including total hours lived and your next birthday.

Common uses

Calculating your exact age for a form, application, or official document
Finding how many days you have lived as a fun personal milestone
Counting down the days until your next birthday or a friend's birthday, or estimate a pregnancy due date from a known conception date
Verifying someone's age eligibility (voting, driving, retirement) alongside a tool that counts days between two dates

Technical specification

Algorithm or formula: Calendar difference using the Gregorian calendar. Years and months are decremented when the end day-of-month precedes the start day-of-month, then remaining days are taken from the prior month length. Hours, minutes, and weekday derive from JavaScript Date arithmetic.
Browser API or library: Native JavaScript Date and Intl.DateTimeFormat. No external library.
Input limits: Any date the browser Date object accepts (roughly -271,821 to +275,760 CE). Practical use covers any human lifespan.
Output: Plain text values displayed in the page. Includes years, months, days, total days, total hours, next birthday date, weekday of birth.
Known limitations: Does not account for time zone changes around the moment of birth. Months are treated as variable-length calendar units, not a fixed 30 days.

Frequently asked questions

How is exact age calculated?: The calculator finds the difference between your date of birth and today in complete years, then counts the remaining months and days. Leap years and months of different lengths are all handled correctly.
Is this age calculator free?: Yes, completely free. No account, no sign-up, and no data is ever sent to our servers.
Do I need to create an account?: No. The tool runs entirely in your browser. Enter your date of birth and the results appear instantly.
What else does the calculator show?: Along with your age in years, months, and days, the calculator shows your total days lived, your age in hours, your next birthday date, how many days until it arrives, and the day of the week you were born.

Reviewed and tested May 25, 2026.