DPMO – Defects Per Million opportunities Calculator

Defects per million opportunities (DPMO) is also known as nonconformities per million opportunities (NPMO).

DPMO is calculated using the below formula:

DPM – Defects Per Million Calculator

DPM is calculated using the below formula:

Sample Size Calculator

Sample Size is calculated using the below formula:


Where CI is the confidence Interval in decimal format. If the Confidence Interval is ±4% then use 0.04
p is Percentage of the sample picking a choice, expressed in decimal. For Sample Size Calculation, we use a p of 0.50
Z value is 1.96 for a Confidence Level of 95%, which is the most commonly used Confidence Level by researchers.A confidence level of 95% means that you are 95% certain about the outcome.

Sample Size Correction For finite Population

The above formula works for bigger populations. For smaller or finite populations, you need to correct the value obtained from the above using the below formula.