Chronbach’s Alpha is a way to measure the internal consistency of a questionnaire or survey.
Cronbach’s Alpha ranges between 0 and 1, with higher values indicating that the survey or questionnaire is more reliable.
The following step-by-step example explains how to calculate Cronbach’s Alpha in Excel.
Step 1: Enter the Data
Suppose a restaurant manager wants to measure overall satisfaction among customers. She decides to send out a survey to 10 customers who can rate the restaurant on a scale of 1 to 3 for various categories.
First, let’s enter the data that contains the survey responses for each of the 10 customers:
Step 2: Perform a Two-Factor ANOVA Without Replication
Next, we’ll perform a two-way ANOVA without replication.
To do so, click the Data tab along the top ribbon and then click the Data Analysis option under the Analysis group:
If you don’t see this option available, you need to first load the Analysis ToolPak.
In the dropdown menu that appears, click Anova: Two-Factor Without Replication and then click OK. In the new window that appears, fill in the following information and then click OK:
The following results will appear:
Step 3: Calculate Cronbach’s Alpha
Next, we’ll use the following formula to calculate Cronbach’s Alpha:
Cronbach’s Alpha turns out to be 0.773.
The following table describes how different values of Cronbach’s Alpha are usually interpreted:
| Cronbach’s Alpha | Internal consistency |
|---|---|
| 0.9 ≤ α | Excellent |
| 0.8 ≤ α < 0.9 | Good |
| 0.7 ≤ α < 0.8 | Acceptable |
| 0.6 ≤ α < 0.7 | Questionable |
| 0.5 ≤ α < 0.6 | Poor |
| α < 0.5 | Unacceptable |
Since we calculated Cronbach’s Alpha to be 0.773, we would say that the internal consistency of this survey is “Acceptable.”
Bonus: Feel free to use this Cronbach’s Alpha Calculator to automatically find Cronbach’s Alpha for a given dataset.
How did you compute the Cronbach’s Alpha on the step 3?
Thank you so much for this! It helped me a lot for my Thesis!
Thanks again so much for this foolproof (hopefully!) guide. I have an acceptable 0.73 🙂
Is this method really realiable to get Cronbach Alpha?
Can you explain how you obtained 124/122 in your cronbach alpha calculation from that data? Thank you.
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This is such a clear explanation. Thank you!
Hello, can you please tell me how can I convert text results from Likert scale (e.g. i totally disagree = 1) to numbers ?
Kind regards,
M
Thanks man
What would be the chronbach alpha value for a sample of 138 participants for a one-way ANOVA
i 22 / i 24
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You are very welcome Eve! Let us know if we can ever help answer any questions.