# How to: Calculate Age

Microsoft Access does not include a function that will calculate the age of a person or thing based on a given date. This topic contains Microsoft Visual Basic for Applications (VBA) code for two custom functions, Age and AgeMonths, that will calculate age based on a given date.

The following function calculates age in years from a given date to today's date.

 `````` Function Age (varBirthDate As Variant) As Integer Dim varAge As Variant If IsNull(varBirthdate) then Age = 0: Exit Function varAge = DateDiff("yyyy", varBirthDate, Now) If Date < DateSerial(Year(Now), Month(varBirthDate), _ Day(varBirthDate)) Then varAge = varAge - 1 End If Age = CInt(varAge) End Function``````

The following function calculates the number of months that have transpired since the last month supplied by the given date. If the given date is a birthday, the function returns the number of months since the last birthday.

 `````` Function AgeMonths(ByVal StartDate As String) As Integer Dim tAge As Double tAge = (DateDiff("m", StartDate, Now)) If (DatePart("d", StartDate) > DatePart("d", Now)) Then tAge = tAge - 1 End If If tAge < 0 Then tAge = tAge + 1 End If AgeMonths = CInt(tAge Mod 12) End Function``````