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Confidence Interval Calculator

Enter the parameters. Calculate a two-sided mean interval and standard error. Review the method and copy or download your results.

Choose the method and enter its numeric settings in the calculator. No file is needed.

Open the calculator, enter your values and review the result.

No account required. Calculations happen in this browser.

  1. Enter the parameters
  2. Check your values and calculation settings.
  3. Calculate, review the method, and save your results.

How it works

Calculate a two-sided mean interval and standard error from your own values. Use the fictional sample to try the calculation. The Student t interval uses sample standard deviation and n − 1 degrees of freedom. Choose z only when the population standard deviation is known. A confidence interval describes a repeated-sampling procedure.

Enter data, review the result, and download it when you are ready. No account is required. Check the input and the output before using them for consequential decisions.

Choose a tool

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