Calculate Age using Date of Birth

HomeExcel FormulasCalculate Age using Date of Birth

Let’s say you are preparing data where the user’s age is one of the important things to capture. The thing is, if you ask every user to enter his/her age, chances are they can give you an approx number.

But here’s the kicker: If you ask them their date of birth then you can easily calculate their accurate age from it.

In Excel, you can calculate a person’s age using different methods, but if you ask me, I have found that the best way is to use DATEDIF.

In today’s post, I’d like to share with you a simple way to calculate age in Excel using the date of birth with DATEDIF.

Quick Intro: DATEDIF

Before you calculate age you need to get a bit deeper into DATEDIF. DATEDIF is a mysterious function that is not listed in Excel’s functions list. But you can enter it and use it once you know what’s its syntax.

This function’s basic work is to calculate the difference between two dates return the result in different ways. i.e. years, months, days or in years and months, month and days, years and days.

And this is the feature that makes it perfect to use in age calculation.



  • Date1 – The date from where you want to start the calculation of your interval.
  • Date2 – The date to which you want to calculate the interval.
  • Interval – It represents the unit of the time, which will return from the function.

Steps to Calculate Age in Excel using DATEDIF

Here you need to calculate age in a format in which you could show years, months, and days separately.

For example, 26 Years, 8 months & 17 days. And for this, we need to combine DATEDIF three times.

calculate age in excel using datedif function and date of birth

Here are the steps.

1. Calculate Completed Years of a Person’s Age

First of all, you need to calculate to total completed years between a date of birth and today’s date. And, for this the formula will be:


This will return completed years between two dates.

2. Calculate Completed Months of a Person’s Age after Completed Years

Next thing is to calculate completed months. It means if you age is 26 Years, 5 months, and 19 days, we need to get 5 months in return.

Below formula can be used:


This will return the completed months between the date of birth and today’s date after completed years.

3. Calculate Completed Days of a Person’s Age after Completed Years and Months

In the end, you need to calculate days that are left after completed years and months. Here is the formula:


This will return the rest of the days between the date of birth and today’s date after completed years and months.

4. Combine All Three Formulas to Get Actual Age

Now it’s time to combine all these to create an accurate age. Enter the below formula in a cell in your worksheet and replace Date-of-Birth with your actual birth date.

=”You age is “& DATEDIF(Date-of-Birth,TODAY(),”y”) &” Year(s), “& DATEDIF(Date-of-Birth,TODAY(),”ym”)& ” Month(s) & “& DATEDIF(Date-of-Birth,TODAY(),”md”)& ” Day(s).”

calculate age in excel using datedif function using date of birth combined formula

That’s all.



You might be wondering if there are other methods that we can use to calculate age. Yes, we have but as I said this is one of the easiest methods to do that. You can calculate a person’s age accurately. I hope you found this formula tip useful. Now tell me one this.

Have you ever calculated age in Excel?

Share your views with me in the comment section, I’d love to hear from you, and please don’t forget to share these tips with your friends.

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  1. When I use DateDif it is working fine in Excel Sheet. But if I use it in VBA it is not accepting. May I have a code for Excel VBA.

  2. I wish to calculate and group my inventory aging, Grouping is like 0- 60 Days , 60 – 90 Days, 90-180 Days

  3. Hi, I working in need in power pivot sheet how to do if condition formula for age, How can I do this calculate

  4. Hello Puneet,
    Is it possible to use this function referenced to TWO cells (i.e., date-of-birth and date-of-visit) to calculate age in certain point of time?