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Date & Age Calculator

Age Calculator

Enter a date of birth to get the exact age in years, months and days, the day of the week you were born, and a countdown to your next birthday.

Today's date — change it to find an age on any other date.

Enter a date of birth to see the exact age.

Age difference calculator

Find out exactly how much older one person is than another.

Enter both dates of birth to compare.

How exact age is calculated

Age is counted the way people normally say it: complete years first, then complete months, then the days left over. Someone born on 10 March 1990 is 36 years, 0 months and 0 days old on 10 March 2026, and still 35 the day before. The calculator follows the same rule for any pair of dates, taking the different lengths of months and leap years into account.

Age on a specific date

“Calculate age on” starts at today's date, but you can change it to any date before or after. That makes it easy to answer questions like how old someone will be on a wedding day, a school cut-off date or a retirement date, or how old a historical figure was at a particular event.

Age in months, weeks, days and hours

Alongside the exact age, the results convert the same span into other units. Months, weeks and days are exact counts of the calendar. Hours are shown as an approximation, since they depend on the time of day you were born. If you're curious about day milestones, the age in days page explains how they are counted.

Birthdays born on February 29

A leap-day birthday only appears on the calendar once every four years. In the other years, this calculator treats February 28 as the birthday, so a person born on 29 February completes another year of age on 28 February. In leap years, the birthday is on 29 February as usual. Legal rules differ: some countries use 1 March instead, so check local regulations if the exact legal date matters.

Age difference between two people

The age difference calculator compares two dates of birth and shows the gap in years, months and days, plus the total number of days and which person is older. The order you enter them in doesn't matter.

Frequently asked questions

How is age calculated?

Age is counted in complete calendar units: first the number of whole years since the date of birth, then whole months, then the remaining days. This is the same way people normally state their age, so someone whose birthday is tomorrow has not yet reached their next year.

How do I calculate my exact age?

Enter your date of birth. The calculator uses today's date automatically and shows your age in years, months and days, plus the same age in total months, weeks, days and approximate hours.

Can I calculate my age on a specific date?

Yes. Change the “Calculate age on” date to any date in the past or future. This is handy for checking an age on a deadline, an event date, or a future birthday.

How many days old am I?

Enter your date of birth and look at “Days” in the results. It is the exact number of calendar days from your date of birth up to today. Hours are shown as an approximation, since the calculator does not know your time of birth.

How does the calculator handle February 29 birthdays?

If you were born on February 29, the calculator treats February 28 as your birthday in years that have no February 29. That means you complete each year of age on February 28 in common years, and on February 29 in leap years. Some countries use March 1 for legal purposes instead, so check local rules if the exact legal date matters.

How do I calculate the age difference between two people?

Use the age difference calculator further down the page. Enter both dates of birth and it shows the gap in years, months and days, the total number of days, and which person is older.

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