## What Is 6 Sigma?

The term “**6 Sigma**” refers to a quality measurement that aims for absolute flawlessness. 6 Sigma is a methodical, computation approach for reducing errors in any process.

The calculation of 6 sigma involves two different approaches. One for discrete data, and another for continuous data.

### Method 1 – Calculation of 6 Sigma with Discrete Data

** Steps:**

The sample dataset showcases the ** Number of Units**,

**and Total**

*Number of Opportunities,***in the**

*Number of Defects***C4:C6**range.

Here, ** U**,

**and**

*O,***represent the**

*D***, the**

*Number of Units***, and the**

*Number of Opportunities***.**

*Number of Defects*- To calculate the
which is defects per opportunity from the previous data, use this generic formula.*DPO,*

**DPO = D / ( U * O )**

- Create an output range in
**C8**.

- Select
**C8**and enter the following formula.

`=C6/(C4*C5)`

- Press
**ENTER**.

The universal formula to get the value of ** 6 Sigma** from

**is the following.**

*DPO***6 Sigma = – NORMSINV (DPO) + 1.5**

- Go to
**C10**and enter the formula below.

`=-NORMSINV(C8)+1.5`

The **NORMSINV function** returns the inverse of the normal distribution.

- Press
**ENTER**.

### Method 2 – Calculation of 6 Sigma With Continuous Data in Excel

This is a continuous dataset, including the **Sample** numbers and their corresponding **Sizes** in columns **B** and **C**.

**Steps:**

The *LSL (*** Lower Specification Limit) **and

**were applied in this dataset. The ideal size is**

*USL (Upper Specification Limit)***32**. A size variation of

**is assumed.**

*+/-1***and**

*LSL***should be**

*USL***31**and

**33**.

`=AVERAGE(C5:C24)`

Use the **AVERAGE function** to calculate the ** Mean**. Here,

**C5:C24**represents the entire data range.

- Press
**ENTER**.

- Go to
**F8**and use the formula below.

`=STDEV(C5:C24)`

The **STDEV function** calculates the standard deviation.

- Press
**ENTER**.

You calculate *C***_{pu}** and

*C***for this dataset. Based on the system’s upper specification limit, the**

_{pl}

*C***is an indicator of its conceivable competence.**

_{pu}

*C***is based on the lower specification limit.**

_{pl}- Select
**F10**and enter the following formula.

`=(F5-F7)/F8`

- Press
**ENTER**.

The value of *C***_{pu}** is 0.07263.

- Go to
**F11**and use the formula below.

`=(F7-F4)/F8`

- Press
**ENTER**.

The ** 6 Sigma Value** would be the minimum value between the values of

*C***and**

_{pu}

*C***divided by the standard deviation.**

_{pl}- Go to
**F13**and enter the following formula.

`=MIN(F10:F11)/F8`

The **MIN function** returns the minimum value from a range of cells.

- Press
**ENTER**.

The value of 6 sigma for continuous data is displayed.

**Read More:**How to Calculate Sigma Level in Excel

## How to Calculate 3 Sigma in Excel

**Steps:**

- Calculate the mean like
**before**. - Select
**F5**and enter the following formula.

`=VAR(C5:C24)`

The **VAR function** returns the variance of a sample taken from population data.

- Press
**ENTER**.

- Select
**F6**and use the following formula.

`=SQRT(F5)`

The **SQRT function** returns the square root of any number. The standard deviation is found from the square root of the variance.

- Press
**ENTER**.

- Go to
**F8**and enter the formula below.

`=3*F6`

- Press
**ENTER**.

- Add the
value with the*Mean*to get the*3 Sigma Value*.*High End Value*

`=F8+F4`

- You can extract the
by subtracting the*Low End Value*from the*Mean*.*3 Sigma Value*

`=F8-F4`

## Practice Section

Practice here.

## Download Practice Workbook

Download the following Excel workbook and practice.

## Related Article

**<< Go Back to Calculate Sigma in Excel | Excel for Statistics | Learn Excel**