Pevlika Browser Apps

Confidence Interval Calculator

Confidence intervals for a mean (t or z) or a proportion.

Runs in your browser — nothing is uploaded
For a

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How to use Confidence Interval Calculator

  1. Enter your values — the unit for each field is shown next to it.
  2. The result updates instantly as you type.
  3. Copy the results, or change inputs to compare scenarios.

Formula & assumptions

Mean: x̄ ± t*·s/√n

Proportion: p̂ ± z*·√(p̂(1 − p̂)/n)

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