Statistics

Sample Size Calculator

Estimate required sample size from confidence level, margin error, and proportion.

Sample Size Calculator estimates required sample size from effect size, confidence, and power assumptions. It is useful for experiment planning and survey design before data collection starts. The tool helps avoid underpowered studies and unnecessary oversampling. Use it to justify data requirements in planning documents.

Sample Size Inputs

Result

Infinite population n: 385

Adjusted n: 385

How to use this tool

Enter expected effect size, confidence level, and desired power.
Run the calculator to estimate minimum sample size.
Adjust assumptions to see how design choices change required n.

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