Yield and PPM calculator
First pass yield (FPY) is the share of units that pass without rework; PPM and DPMO express the same defects per million units or per million opportunities, and the sigma level places them on the Six Sigma scale. Add step yields to get the rolled throughput yield of a whole process.
Result
How to use this tool
- Enter the units that entered the process and how many failed the first inspection.
- Keep opportunities at 1 for PPM-style reporting, or enter the number of ways a unit can fail to get DPMO.
- Paste the yield of each step to get the rolled throughput yield of the whole line.
Good to know
- Rework is counted as a first-pass failure; a unit fixed and shipped still lowers FPY.
Frequently asked questions
How are yield, PPM and DPMO calculated?
First pass yield is (units started − defective units) ÷ units started. PPM is the defect rate × 1,000,000, so 120 defects in 10,000 units is 98.8% yield and 12,000 PPM. DPMO divides the defects by units × opportunities, which lets products with different complexity be compared on one scale.
How is the sigma level worked out?
The calculator converts DPMO to a long-term probability, looks up the standard normal quantile and adds the conventional 1.5 sigma shift. 12,000 DPMO gives about 3.76 sigma; 3.4 DPMO is the familiar 6 sigma. The shift is a convention, so some tables will differ by exactly 1.5.
What is rolled throughput yield?
Rolled throughput yield multiplies the first pass yield of every step, so it shows the chance that a unit passes the whole process without any rework. Three steps at 98.5%, 99.2% and 97.8% give 95.6%, which is lower than any single step and is why small losses at many stations add up.
Results are estimates for general information. Double-check anything important with an official source.