Confidence Interval Calculator for a Single Mean

  • Provides live interpretations.
  • Assesses the influence of changing input values.
  • Supports z-distribution and t-distribution.

Input Values

Specify input values and click Calculate. Hover over for help.

  0.95

Note: Use the t-distribution when the standard deviation was estimated from the sample (the usual case). Use the z-distribution only when the population standard deviation is known.


Influence of Changing Input Values on Confidence Interval Width

Customize Visualisation

Customize the plot by changing input values from here.

From Min
To Max
By
1st Series
2nd Series
3rd Series

Visualisation

This visualisation plots CI width for three sample sizes as the standard deviation varies. You may change the default values from the 'Customize Visualisation' panel.

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Table of Confidence Interval Widths at a range of Standard Deviations and Sample Sizes

Customize Table

Customize the table by changing input values from here.

From Min
To Max
By
From Min
To Max
By

Confidence Interval Width Table

This table shows CI widths for a range of standard deviations and sample sizes. You may change the default input values from the panel on the left.

Download Table