CONFIDENCE.NORM Function in Excel: Margin of Error

⏱ 1 min readUpdated 28 September 2026

StatisticsLevel: ExpertAvailable in: Excel 2010+

In this article
  1. Syntax
  2. Examples
  3. Example 1
  4. Related functions

CONFIDENCE.NORM gives the ± margin around a sample mean for a chosen confidence level.

Syntax

=CONFIDENCE.NORM(alpha, standard_dev, size)
Argument What it means
alpha 0.05 for 95% confidence.

Examples

Example 1

=CONFIDENCE.NORM(0.05, 12, 100)

About 2.35: the true mean is likely within ±2.35 of your sample mean.

NORM.INV · STDEV.S

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