Dates & Time

Excel formula for Calculate age from a birth date

Get a person's age in whole years from their date of birth.

Copy this formula

=DATEDIF(A2, TODAY(), "Y")

How the formula works

DATEDIF measures the difference between the birth date and today. The "Y" unit returns complete years, correctly accounting for whether this year's birthday has passed.

Examples

=DATEDIF("1990-06-23", TODAY(), "Y")→36

Age in completed years as of today.

=DATEDIF(DATE(2000,3,15), DATE(2026,3,14), "Y")→25

The day before the 26th birthday still counts as 25.

=INT(YEARFRAC(A2, TODAY()))→36

An alternative that does not rely on DATEDIF.

Other ways to do this

Years and months

=DATEDIF(A2, TODAY(), "Y") & "y " & DATEDIF(A2, TODAY(), "ym") & "m"

Shows age like "36y 0m".

FAQ

Will the age update automatically?

Yes — TODAY() recalculates each day the workbook opens, so the age stays current.

Why is DATEDIF missing from the function list?

DATEDIF is an undocumented compatibility function, so Excel does not suggest it as you type. It still works when you enter it in full.

How do I calculate age on a specific date?

Replace TODAY() with that date: =DATEDIF(A2, DATE(2026,12,31), "Y").

Why does DATEDIF return #NUM!?

The start date is later than the end date. Put the birth date first and the later date second.

Related formulas

Days between two dates Add or subtract months from a date

Functions used

DATEDIF TODAY

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