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Kordu Tools
Time & Date Runs in browser Updated 30 Mar 2026

Age Calculator

Calculate your exact age in years, months, and days with birthday countdown and zodiac sign.

Your age

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Time alive

Total years

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Total months

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Total weeks

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Total days

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Total hours

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Total minutes

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Birthday

Next birthday

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Days until

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Birthdays had

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About you

Western zodiac

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Chinese zodiac

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Generation

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Born in

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Leap years lived

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Christmases

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Fun facts

Heartbeats

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Based on 72 bpm average

Breaths taken

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Based on 16/min average

Time spent sleeping

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Based on 8 hours/day

Life milestones

Enter your date of birth to see your age breakdown.
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How to use Age Calculator

  1. Enter your date of birth

    Use the date picker to select the day, month, and year you were born. You can type it directly or use the calendar.

  2. Review your exact age

    See your age broken down into years, months, and days, plus the total number of days you have been alive.

  3. Check your birthday details

    View your next birthday date, the number of days until it arrives, and the day of the week you were born.

  4. See your zodiac sign

    Your Western zodiac sign is shown automatically based on your birth month and day.

  5. Calculate age at a specific date

    Adjust the 'As of' date to any past or future date to see what your age was or will be on that day.

Age Calculator FAQ

How is the exact age calculated?
Age is calculated using calendar duration — counting complete years from the birth month and day, then remaining complete months, then remaining days. This matches how age is legally and commonly understood.

How does it handle leap year birthdays?
For people born on February 29th, the birthday is observed on February 28th in non-leap years for the purposes of next birthday countdown. The age calculation always uses calendar duration, which handles this correctly.

Which zodiac system does it use?
Western tropical astrology — the twelve signs follow the standard date ranges used in most Western horoscope systems (e.g. Aries: 21 March – 19 April).

Can I calculate age at a future date?
Yes. Change the 'As of' date to any future date to see what your age will be on that day. Useful for checking whether you will have met an age requirement by a specific deadline.

Can I calculate age at a past date?
Yes. Set the 'As of' date to any past date to find out how old someone was on a historical date — useful for genealogy, legal documents, or historical research.

How many days alive is calculated?
It counts the total number of calendar days from your date of birth to the selected 'As of' date, inclusive of both the birth date and the reference date. Leap years add an extra day in those years.

How accurate is the birthday countdown?
The countdown is based on your local device date, so it is accurate to the day. It does not account for timezone differences — if you were born in a different timezone, the day of birth was the same calendar date you enter.

Can I use this to check legal age requirements?
Yes. Set the 'As of' date to the date of an event or application and the tool shows your exact age on that day. Always verify with the official authority for legal decisions.

What day of the week was I born?
The tool calculates the day of the week using the Gregorian calendar, accounting correctly for the calendar reforms and leap year rules. The result is shown below your age.

Is any data sent to a server?
No. All age calculations happen in your browser using standard JavaScript date arithmetic. Your date of birth is never transmitted anywhere.

Why might my age differ from what another calculator shows?
Some calculators use simple year subtraction without adjusting for whether the birthday has occurred yet in the current year. This tool uses full calendar duration, which is the correct method.

Background

Enter your date of birth to see your exact age broken down into years, months, and days. View the total number of days you have been alive, the date of your next birthday, how many days until it, the day of the week you were born, and your Western zodiac sign. Optionally change the "as of" date to calculate age at any point in time — useful for legal age checks, anniversary calculations, or finding out how old someone was on a particular date. Correctly handles leap years so February 29th birthdays are calculated accurately. All calculations run locally in your browser with no data sent anywhere.

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