Sample Size Calculator for Means
Determine the sample size needed to estimate a population mean
Estimate from pilot study or similar research
Half-width of confidence interval (same units as SD)
About Sample Size for Means
Formula: n = (z × σ / e)²
Key insight: Halving the margin of error quadruples the sample size.
Tip: If σ is unknown, use range/4 or range/6 as an estimate.
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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.