Calculating Age of the person in T-SQL

One of common calculations, we have to do in ETL is calculating age of the person from the date attribute

And this is how I have calculated Age of the person.

Select BirthDate,

CASE

            WHEN Month(GetDate()) < Month(c.[BirthDate])

                THEN DateDiff(yy,c.[BirthDate],GetDate()) - 1

            WHEN Month(GetDate()) = Month(c.[BirthDate])

            AND Day(GetDate()) < Day(c.[BirthDate])

                THEN DateDiff(yy,c.[BirthDate],GetDate()) - 1

            ELSE DateDiff(yy,c.[BirthDate],GetDate())

        END AS [Age]

              from [dbo].[DimCustomer] c

              order by BirthDate

I am sure, there would be other better ways to do this and would love to hear, of how you have calculated age of the person