CPK Calculator

Calculate CPK







Formula

The formula to calculate the CPK (Process Capability Index) is:

\[ CPK = \min\left(\frac{USL - \text{mean}}{3 \cdot \text{std}}, \frac{\text{mean} - LSL}{3 \cdot \text{std}}\right) \]

Where:

What is CPK?

CPK is defined as the process capability index and is a measure of the ability of a process to produce objects to a customer's specifications.

Example Calculation

Let's assume the following values:

Using the formula to calculate the CPK:

\[ CPK = \min\left(\frac{10 - 6}{3 \cdot 1}, \frac{6 - 2}{3 \cdot 1}\right) = \min\left(\frac{4}{3}, \frac{4}{3}\right) = 1.33 \]

The CPK is 1.33.