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Confidence Interval for a Mean

Calculate Confidence Interval for a Mean instantly. Free online calculator with the exact formula, a worked example, and metric units. No signup required.

Confidence Interval for a Mean

Mean
σ
n
CI95% half-width
5.3677
CI: [94,63, 105,37]z = 1.96Calculate Confidence Interval for a Mean instantly. Free online calculator with the exact formula, a worked example, and metric units. No signup required.

More about: Confidence Interval for a Mean

What it calculates

The “Confidence Interval for a Mean” calculator computes CI95% half-width from 3 parameters: mean, σ, n.

A core calculation for studying, engineering tasks, and checking solutions.

Example calculation

With parameters Mean = 100, σ = 15, n = 30 the result is 5.37 (CI: [94,63, 105,37]).

How to use

  1. Enter the parameter values — every field above is adjustable with a slider.
  2. The result and related metrics are calculated automatically as you type.
  3. Use the additional metrics shown (if any) where needed.
  4. Copy the result or bookmark the page.

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