basic

Margin of Error from Sample Size Calculator

E = z · σ / √n at a chosen confidence level.

Compute the margin of error E for the mean from the sample standard deviation, sample size, and chosen confidence level (90, 95, 99%) using E = z · s / √n.

Daniel Oh By Daniel Oh
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

E = z · s / √n

In depth

Compute the margin of error E for the mean from the sample standard deviation, sample size, and chosen confidence level (90, 95, 99%) using E = z · s / √n.