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Cp Calculator
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Process capability compares the given sample to its specification limits by using capability indices.The process capability cp is given by
Cp formula = $\frac{USL−LSL}{6 \times standard\ deviation}$
Here USL is upper specification limit
LSL is lower specification limit
Capability process Calculator (Cp Calculator) is a online tool to calculate the process capability. Enter the given quantities namely Upper specification Limit (USL), lower specification Limit (LSL) and standard deviation (σ) in block provided and get the answer of Cp instantly.

## Steps for Cp Calculator

Step 1 :

Read the problem and observe whether upper specification Limit (USL), lower specification Limit (LSL) and standard deviation ($\sigma$) are given.

Step 2 :

To calculate the Cp use the formula

Cp formula = $\frac{USL - LSL}{6 \times standard\ deviation}$

Here USL is upper specification limit
LSL is lower specification limit

Substitute the values in the above formula and get the answer.

## Problems on Cp Calculator

1. ### In a certain machine the specification limit is 6-12. If the average value is 7 and standard deviation is 4. Calculate the Cp value.

Step 1 :

Given: Upper specification limit USL = 12, Lower specification limit LSL = 6, Mean = 7 and standard deviation $\sigma$ = 4

Step 2 :

The Cp formula is given by
Cp = $\frac{USL - LSL}{6 \times standard\ deviation}$

= $\frac{12 - 6}{6 \times 4}$

= $\frac{6}{24}$

= 0.25

The Cp value is 0.25.

2. ### A machine manufactures certain part with a diameter of 3 inches. If its specification limit is between 2.85 and 3 inches and has a standard deviation of 0.05. Calculate its Cp value.

Step 1 :

Given: Upper specification limit USL = 3, Lower specification limit LSL = 2.85 and standard deviation $\sigma$ = 0.05

Step 2 :

The Cp formula is given by
Cp = $\frac{USL - LSL}{6 \times standard\ deviation}$

= $\frac{3 - 2.85}{6 \times 0.05}$

= $\frac{0.15}{0.05}$
= 0.5