I think you need to be more specific about formulas you're asking for.
I'll give you a few and see if that's what you're asking for:
DPU=Defects/Units
DPMOp=DPMO=PPM=Total 1,000,000*(Defects/Opportunities)
DPMOp=1,000,000*(DPU/Opportunities
SIGMA = SQRT(LN(1/(1-EXP(-DPMOP/1000000))^2))-(2.55155+0.802853*SQRT(LN(1/
(1-EXP(-DPMOP/1000000))^2))+0.010328*SQRT(LN(1/(1-EXP(-DPMOP/1000000))^2))^2)/
(1+1.432788*SQRT(LN(1/(1-EXP(-DPMOP/1000000))^2))+0.189269*SQRT(LN(1/
(1-EXP(-DPMOP/1000000))^2))^2+0.001308*SQRT(LN(1/(1-EXP(-DPMOP/1000000))^2))^3)+1.5
where DPMOP=defects per million opportunities
First Time Yield=
#UnitsPassing1stInspection/#UnitsInspected
approx= e^-DPU
RolledUpYield=
#UnitsCompleteingProcess/#UnitsProcessed
approx= e^(DPU1+DPU2+DPU3...)
where DPU1, DPU2, DPU3 represent the defect rate of process steps 1`, 2, 3, ...