Calculation 1 : OK
OT Hrs: IIf([Production Details]![Depositing Qty Overtime]<30,0,Round(([Production Details]![End Time]-[Production Details]![End Work])*24,2))
Calculation 2 : Not OK :banghead:
=Nz([OT Qty],0)/Nz([OT Hrs],0)
The result still the came out #Num! in the event 0 OT.