Free · Math · Statistics & Probability

Confidence Interval Calculator

Estimate a normal-theory confidence interval for a mean from a sample mean, deviation, and size.

  • Calculation method included
  • Private in your browser
  • No signup
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Calculator inputs

Enter your values

Result

Your calculation

Confidence interval
50.04 to 53.96
Margin of error
±1.96
Standard error
1

This uses a normal critical value. Small samples may require a t critical value.

How to use this calculator

  1. Enter the known values using the units shown.
  2. Choose the calculation you want when more than one method is available.
  3. Calculate, then review the result and the worked formula together.

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Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

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