How to calculate age (in years) based on Date of Birth and getDate()

Question

I have a table listing people along with their date of birth (currently a nvarchar(25))

How can I convert that to a date, and then calculate their age in years?

Answer 1

DECLARE @DOB datetime
set @DOB ='11/25/1985'

select floor(
( cast(convert(varchar(8),getdate(),112) as int)-
cast(convert(varchar(8),@DOB,112) as int) ) / 10000
)

source: http://beginsql.wordpress.com/2012/04/26/how-to-calculate-age-in-sql-server/