Sample Size Calculator
Round-up sample size for proportion or mean modes using z critical.
Limitation: Educational survey planning—assumes simple random sampling and stated inputs.
How to Use the Sample Size Calculator
Round-up sample size for proportion or mean modes using z critical.
Open the Sample Size calculator and read field labels.
Match the mode
Educational survey planning—assumes simple random sampling and stated inputs.
What It Calculates
Round-up sample size for proportion or mean modes using z critical.
Worked Examples
Proportion p=0.5 E=0.05
Inputs
Result
Classic poll sizing.
Mean σ=10 E=2
Inputs
Result
(1.96×10/2)² rounded up.
90% confidence
Inputs
Result
Smaller z*.
Check your mode
Educational survey planning—assumes simple random sampling and stated inputs.
Frequently Asked Questions
Still have questions about this calculation?
Try the CalculatorFormulas
Standard definitions with assumptions noted below.
Formula
Scientific Background
Standard statistics definitions with assumptions stated on-page. Educational only—not professional certification.
Sources & review
Sample Size Calculator documents the references behind its formulas and assumptions. Always treat results as educational estimates, not personalized professional advice.
Last reviewed
July 22, 2026
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