Our age calculator quickly finds your exact age in years, months, and days based on your date of birth. You can also calculate the time between any two dates in different ways, whether you need the difference in years, months, weeks, days, hours, minutes, or even seconds.
It’s a helpful tool if you’ve ever wondered, “How many days old am I?” or “How many hours have I lived?” In just a few clicks, you’ll get detailed results in multiple units of time.
New Feature: You can now calculate your approximate date of birth if you only know your age. Simply go to the settings, choose the “Age” option, and the calculator will switch to find a birthdate based on the age you enter.
What is My Age Today?
This age calculator lets you instantly find out your current age. Enter your date of birth and today’s date (or any other date), and see your exact age at that moment. You’ll also see how many days remain until your next birthday or a special date you pick.
How Old is My Baby?
Parents often need to know the age of their newborn or infant in weeks and months. With this calculator, you can quickly find out how many weeks or months old your child is. Just enter the birth date, and the calculator will show you the age in weeks, months, and days. It’s great for keeping track of milestones and doctor visits!
How Age is Calculated
This calculator uses two different methods:
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General method: Calculates age in years, months, and days, treating every month as an average of 30.4167 days and every year as 365 days.
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Exact day method: Counts the exact number of days between two dates, properly accounting for leap years and different month lengths.
For example, when finding age in years and months, it uses standard-length assumptions. But when finding total days alive, it precisely counts the actual number of days including leap years.
The math behind it:
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Regular years: 365 days × number of years
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Leap years: 366 days × number of leap years
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Plus the number of days in the remaining part of the year
This approach ensures you get an accurate age calculation, whether you need it in days, months, or complete years.
How Many Days Until a Special Date?
Planning a birthday, vacation, or important event? You can easily find out how many days are left. Just enter today’s date and your target date into the calculator. It will tell you exactly how many days you have to wait!
Days in Each Month:
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January: 31
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February: 28 (29 in leap years)
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March: 31
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April: 30
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May: 31
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June: 30
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July: 31
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August: 31
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September: 30
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October: 31
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November: 30
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December: 31
If you’re counting days by hand, remember to account for leap years and the exact number of days in each month. Or simply let the calculator handle it for you!
Date Inputs Made Easy
When entering dates, you can use single digits (like “3” instead of “03”) and just make sure to enter a full 4-digit year.
The calculator counts from day 0, meaning the starting date is not included. For example, from March 15 to March 18 is counted as 3 full days.
How to Calculate Age in Excel
If you want to create a similar age calculation in Excel:
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To find years:
=DATEDIF(A1, TODAY(), "Y") -
To find months after full years:
=DATEDIF(A1, TODAY(), "YM") -
To find days after full months:
=DATEDIF(A1, TODAY(), "MD")
You can combine these for a full age display using =CONCAT(A2, " years, ", A3, " months, ", A4, " days"), where A2, A3, and A4 are your calculated cells.
Feel free to use this calculator whenever you need to know your exact age or time between two dates — down to the last second!
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