overtime calculation

 I am trying to calculate overtime by day and then have the column total up correctly.

Right now I have a measure that if the total hours worked for the day is greater than 8 then total the hours up and subtract by 8.

This works great fora  given day.  However the week total then is total hours worked-8.  In the example below i get 52.25.  When in reality I should get 20.25.

OT2 = IF(CALCULATE(SUM(RC_AoD_EmployeeSummsByFilekey[HoursHund]))>8,CALCULATE(SUM(RC_AoD_EmployeeSummsByFilekey[HoursHund]))-8,0)

Name        10/20/2016 10/21/2016 10/22/2016 10/23/2016 10/24/2016 Grand Total Total OT
John Doe          4                  4.25           3.75            4.25              4                  52.25       20.25