basic

Confidence Interval for Proportion Calculator

p̂ ± z × √(p̂(1−p̂)/n) — CI for a sample proportion.

Calculates the confidence interval for a population proportion from sample proportion, sample size, and chosen confidence level.

Marcus Laurent By Marcus Laurent
Published Last reviewed 1 min read

Inputs

Results

Enter values and click Calculate to see results.
Was this helpful?

How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

CI = p̂ ± z × √(p̂(1−p̂)/n)

In depth

Calculates the confidence interval for a population proportion from sample proportion, sample size, and chosen confidence level.