Formula problem

[rawilkins]

lpad(floor((to_days(now())-to_days(table1.field9))/365.25),2,'0')

the above formula is to calcuate age based on birthdate, it does but it is 1 year shy of correct date, and ideas why? I also would like to see if I can calcuate age as of a set date. I mean if you are 21 by July 31 I want your age shown as 22 if after July 21 ages is 21

[planetsim]

Im assuming your doing this in a database. There is an example on how to do this on http://dev.mysql.com/doc/mysql/en/date-calculations.html