Confidence Interval Calculator

Calculate Wilson, exact, Wald, and mean confidence intervals with the method and assumptions shown.

Interval type

Confidence interval

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Wilson is the default for proportions.

Calculation details
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Wilson: (p + z^2/(2n)) / (1 + z^2/n), with Wilson half-width How?

How this is calculated

Proportion intervals default to Wilson score because it behaves better near 0 and 1 than the plain Wald interval. Clopper-Pearson exact is available for binomial boundary cases, and mean intervals use the one-sample t interval with sample SD.

Formula: Wilson: (p + z^2/(2n)) / (1 + z^2/n), with Wilson half-width

Sources

  1. statsmodels proportion_confint. statsmodels. Retrieved .
  2. NIST SEMATECH e-Handbook confidence intervals. NIST. Retrieved .

Method last reviewed