SEM Calculator

Calculate the Standard Error of the Mean

About Standard Error of the Mean

The Standard Error of the Mean (SEM) measures how precisely the sample mean estimates the population mean. It decreases as sample size increases.

Formula: SEM = s / √n

Where s is the sample standard deviation and n is the sample size.

Key Points:

  • SEM is always smaller than the standard deviation
  • Larger samples produce smaller SEM (more precise estimates)
  • SEM is used to construct confidence intervals for the mean
  • Quadrupling the sample size halves the SEM
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Editorial Note

MyCalcBuddy Editorial Team

This page is maintained as an educational calculator reference.

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Formula Source: Standard Mathematical References

by Various

🔄Last reviewed: May 2026
✓Formula checks are based on standard references and internal QA review.