Excel is the most widely used tool for dealing with massive datasets. We can perform myriads of tasks of multiple dimensions in Excel. In this article, I will show you how to plot Weibull Distribution in Excel.

**Table of Contents**Expand

## Introduction to Weibull Distribution

The **Weibull Distribution** is a continuous probability distribution that is used to analyze life data, model failure times, and assess the reliability of access products.Â This distribution can be used largely in different fields to analyze data.

**Reliability Function R(t) = e^-[{(t-Î³)/Î±}^Î²]**

Where,

**Î² = Shape Parameter
**

**Î± = Scale Parameter**

**Î³ = Location Parameter.**This is usually

**0**.

From

**R(t)**, we can get the Failure function

**F(t)**

**F(t) = 1-R(t)**

After calculation, we get

**ln(ln(1/(1-F(t))) = Î²lnt-Î²lnÎ±
**This resembles the

**y=mx+c**equation

## How to Plot Weibull Distribution in Excel: 4 Quick Steps

This is the dataset for todayâ€™s article. We have the instances of failure and the number of days for the failure. For example, the 1st failure occurs after 400 days, 2nd one after 820 days.

I will use this data to get the **Weibull Distribution** and understand the failure rate.

### Step 1: Calculate Median Rank

The first step is to calculate the median rank. To calculate this, we will use Bernardâ€™s approximation.

- Go to
**D5**and write down the following formula

`=(B5-0.3)/($B$14+0.4)`

- Then, press
**ENTER**to get the output.

- After that, use the Fill Handle to AutoFill up to
**D14**.

### Step 2: Determine Natural Logarithm

The next step is to calculate the natural logarithm as per the requirement. First, we will determine the logarithm of days. To do so,

- Go to
**E5**and write down the following formula

`=LN(C5)`

- Then, press
**ENTER**to get the output.

- After that, use
**Fill Handle**to**AutoFill**up to**E14**.

- In a similar way, we will fill up the next column. The formula in
**F5**will be

`=LN(LN(1/(1-D5)))`

- Then, press
**ENTER**to get the output.

- After that, use
**Fill Handle**to**AutoFill**up to**F14**.

### Step 3: Plot Distribution Chart

The next step is to plot a chart using **ln(days)** as x-axis and **ln(ln(1/(1-F(t)))) **as y-axis. To do so,

- Select
**E4:F14**.

- Then, go to the
**Insert** - After that, choose the
**Scatter** - Finally, select the one you like.

**Excel**will create a scatter plot.- Rename the plot to Weibull
**Distribution**.

**Read More: **How to Create a Distribution Chart in Excel

### Step 4: Compare Equation to Determine Coefficients

Now, we will determine the parameters. We will get the trendline equation and compare it with the equation **ln(ln(1/(1-F(t))) = Î²lnt-Î²lnÎ±**

- Go to
**Chart Design**. - Then, go to
**Add Chart Element**. - After that choose a
**Trendline**.

**Excel**will add a trendline.and__Select the trendline__**right-click**your mouse.- Then, select
**Format Trendline**.

- After that, mark the box for
**Display Equation on Chart**.

**Excel**will show the equation.

- The equation is
**y=1.9551x-14.663**. After comparing with**ln(ln(1/(1-F(t))) = Î²lnt-Î²lnÎ±,**we get**Î² = 1.9551****Î²lnÎ± = 14.663**

- Using these values, we get
**Î± = 1807.811**

** **

- So, the
**Reliability Function**becomes

**R(t) = e^-[(t/1807.811)^1.9551]**

## Things to Remember

The shape parameter indicates the failure rate.

- If
**Î² < 1**, then the failure rate decreases with time - If
**Î²****= 1**, then the failure rate is constant - If
**Î² > 1**, the failure rate increases with time

Use absolute reference to lock a cell.

**Download Practice Workbook**

Download this workbook and practice while going through the article.

## Conclusion

In this article, I have explained how to plot Weibull Distribution in Excel. I hope it helps everyone. If you have any suggestions, ideas, or feedback, please feel free to comment below. Please visit Exceldemy for more useful articles like this.

## Related Articles

- How to Plot Normal Distribution in Excel
- Plot Normal Distribution in Excel with Mean and Standard Deviation
- How to Plot Frequency Distribution in Excel
- How to Plot Poisson Distribution in Excel
- How to Plot Particle Size Distribution Curve in Excel
- How to Create a Probability Distribution Graph in Excel

**<< Go Back to Excel Distribution ChartÂ |Â Excel ChartsÂ |Â Learn Excel**

Thank you so much for your contribuition!

Dear

Tiago,You are most welcome.

Regards

ExcelDemyDo you know how could I implement suspesions data in such analisys?

Dear Tiago

To implement suspension data in a Weibull Distribution, follow these steps:

â€¢Collect completed failure data and suspended data.

â€¢Estimate Weibull distribution parameters (shape and scale) using standard methods for completed data.

â€¢Determine the truncation point for suspended data.

â€¢Modify the Weibull PDF and CDF formulas to account for truncation.

â€¢Estimate parameters for suspended data using methods that consider truncation.

â€¢Evaluate the model’s fit using techniques like Q-Q plots or statistical tests.

Thank you.

Thank you Mr. Rashid! I got it, I finished my work here using the MRR method. Have you done some similar work with Maximum Likelihood Estimation (MLE) for Weibull?

Dear Tiago

It’s good to know that you have finished your work successfully. No, I have not tried the MLE method for Weibull Distribution yet.

Thank you. Have a good day!