How to Calculate Age in Excel From DOB – A Step-by-Step Guide

Calculating someone’s age in Excel from their date of birth (DOB) is a piece of cake! All it takes is a simple formula, and you’ll have the precise age in years in no time. This article will guide you through the steps to accomplish that, so let’s dive right in!

Step by Step Tutorial: Calculate Age in Excel from DOB

Before we start with the steps, know that we’re about to use some Excel magic to turn dates into age. We’ll employ a formula that compares the date of birth of a person to today’s date, and voilà, you’ll have the age.

Step 1: Enter the date of birth

Type the date of birth in one cell of the Excel spreadsheet.

The cell can be formatted in various ways to display the date, but as long as Excel recognizes it as a date, the calculation will work.

Step 2: Use the TODAY function

In a new cell, type the formula =TODAY().

This function ensures that Excel uses the current date as a reference point for calculating age.

Step 3: Subtract DOB from today’s date

In another cell, subtract the DOB from the result of the TODAY function.

This gives you the number of days between the two dates.

Step 4: Divide by 365.25

Divide the result by 365.25, which accounts for leap years.

This division converts the number of days into years, giving you an approximate age.

Step 5: Round down the result

Finally, use the FLOOR function to round down the result to the nearest whole number.

This step ensures that you get the completed years, which is the standard way to express age.

Once you’ve followed these steps, you’ll see the age displayed in the cell where you applied the formula. Now, wasn’t that easy?

Tips: Excel Age Calculation from DOB

  • Use the DATE function to ensure the DOB is entered in a consistent format.
  • To calculate age as of a specific date, replace the TODAY function with that date.
  • If the age comes out as a decimal, remember to round down for an accurate age.
  • Always check that your computer’s system date is correct, as it will affect the TODAY function.
  • Excel stores dates as serial numbers, so ensure you format the cell correctly to display a date.

Frequently Asked Questions

What if I want to calculate age in months?

To calculate the age in months, multiply the result of the age formula by 12.

How can I format the age result to include “years”?

After the formula, add & ” years” to concatenate the text “years” to the age result.

Can I use this formula to calculate age for a list of DOBs?

Yes, you can apply the same formula to a column of DOBs to calculate age for each entry.

What if my DOB is in a different date format?

Excel can handle various date formats. Just ensure the cell is formatted as a date, and the formula will work.

Why do we divide by 365.25 and not 365?

We divide by 365.25 to account for leap years, which adds an extra day every four years.


  1. Enter DOB
  2. Use TODAY function
  3. Subtract DOB from today’s date
  4. Divide by 365.25
  5. Round down the result


There you have it, folks! Calculating age in Excel from someone’s date of birth is as simple as following a few easy steps. Whether you’re maintaining employee records, organizing event participants, or just curious about a friend’s age, Excel is the perfect tool for the job. Not only is it efficient, but it also eliminates human error, giving you accurate results every single time.

Remember, the key is to ensure that Excel recognizes the date format and your system clock is accurate. Be mindful of those leap years; they’re sneaky but important in getting the calculations just right. And don’t forget to round down the final result to express the age correctly.

Now that you’re equipped with this knowledge, why not take a stab at it? Try calculating your own age or that of a family member. Get comfortable with the formula, and soon, you’ll be the go-to Excel wizard when anyone needs to find out someone’s age. Enjoy crunching those numbers, and happy calculating!

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