Usability, Customer Experience & Statistics

Confidence Interval Calculator

Jeff Sauro • March 21, 2012

Compute confidence intervals around continuous data using either raw or summary data.

Enter Summarized Data
Sample Data
Confidence Level :

Show Sample Data
NMeanStDevSE Mean

About Jeff Sauro

Jeff Sauro is the founding principal of MeasuringU, a company providing statistics and usability consulting to Fortune 1000 companies.
He is the author of over 20 journal articles and 5 books on statistics and the user-experience.
More about Jeff...

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Posted Comments

There are 9 Comments

September 21, 2016 | Tracey Danny wrote:

Dr Hope is a very genuine spell caster and a very unique and a powerful man of wisdom. Dr Hope brought back joy to my life and to my family again by bringing my husband back to me, by curing my sister's cancer disease and by also curing my cousin's hiv virus with his special powers. Dr Hope is really a gifted, amazing, and a very good man who truly knows how to do his job better and if not for him what would my life turn to? Dr Hope thank you so much and i will never stop talking about your great deeds. Words can not express how much good you have done for me and my family and i believe that even a thousand words won't be enough to describe your good great works. If you are in need of any spiritual help why not run to Dr Hope? just contact Dr Hope on his email: or you can also contact him on his web site on: and he will help you. Contact him now and get your solution. Thank you Dr Hope for you are indeed a great man. 

May 16, 2016 | Earl wrote:

this calc is for a complete set of raw data. if you only have a sample you need a different calculator 

August 16, 2015 | Grady wrote:

.needs to give accurate readings, like measure at LEAST to the nearest thousandth 

April 30, 2013 | Carlos Bento wrote:

I fill easy to use and quick 

July 15, 2012 | Yoda wrote:

This was WAY off 

May 19, 2012 | Mara wrote:

take home* 

May 19, 2012 | Mara wrote:

I just used this to check my answers for a take hoe final and it was only a few decimals off, awesome! 

May 10, 2012 | mark wrote:

helped me out while taking a final 

April 19, 2012 | wayne wrote:

excellent calculator  

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Jeff's Books

Customer Analytics for DummiesCustomer Analytics for Dummies

A guidebook for measuring the customer experience

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Quantifying the User Experience 2nd Ed.: Practical Statistics for User ResearchQuantifying the User Experience 2nd Ed.: Practical Statistics for User Research

The most comprehensive statistical resource for UX Professionals

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Excel & R Companion to Quantifying the User ExperienceExcel & R Companion to Quantifying the User Experience

Detailed Steps to Solve over 100 Examples and Exercises in the Excel Calculator and R

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A Practical Guide to the System Usability ScaleA Practical Guide to the System Usability Scale

Background, Benchmarks & Best Practices for the most popular usability questionnaire

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A Practical Guide to Measuring UsabilityA Practical Guide to Measuring Usability

72 Answers to the Most Common Questions about Quantifying the Usability of Websites and Software

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