You can use the following formulas to convert date of birth to age in Excel:
Formula 1: Convert Date of Birth to Age in Years (e.g. 23 years)
=DATEDIF(A2,NOW(),"y")
Formula 2: Convert Date of Birth to Age in Decimal Years (e.g. 23.567 years)
=YEARFRAC(A2,NOW())
Formula 3: Convert Date of Birth to Age in Years, Months, Days (e.g. 23 years, 6 months, 25 days)
=DATEDIF(A2,NOW(),"y")&" years, "&DATEDIF(A2,NOW(),"ym")&" months, "&DATEDIF(A2,NOW(),"md")&" days"
Each formula assumes that the date of birth is located in cell A2.
The following examples show how to use each formula in practice with the following list of birth dates in Excel:
Example 1: Convert Date of Birth to Age in Years
To convert the date of birth to age for cell A2, we can type the following formula into cell B2:
=DATEDIF(A2,NOW(),"y")
We can then click and drag this formula down to each remaining cell in column B:
Column B displays the age for each birth date in column A in terms of years.
Example 2: Convert Date of Birth to Age in Decimal Years
To convert the date of birth to an age in decimal years for cell A2, we can type the following formula into cell B2:
=YEARFRAC(A2,NOW())
We can then click and drag this formula down to each remaining cell in column B:
Column B displays the age for each birth date in column A in terms of decimal years.
Example 3: Convert Date of Birth to Age in Years, Months, Days
To convert the date of birth to an age in years, months and days for cell A2, we can type the following formula into cell B2:
=DATEDIF(A2,NOW(),"y")&" years, "&DATEDIF(A2,NOW(),"ym")&" months, "&DATEDIF(A2,NOW(),"md")&" days"
We can then click and drag this formula down to each remaining cell in column B:
Column B displays the age for each birth date in column A in terms of years, months, and days.
Additional Resources
The following tutorials explain how to perform other common tasks in Excel:
How to Calculate the Number of Months Between Dates in Excel
How to Convert Date to Month and Year Format in Excel
How to Calculate Average by Month in Excel