This free sample size calculator determines the sample size required to meet a given set of constraints. Also, learn more about population standard deviation.

You can use this free sample size calculator to determine the sample size of a given survey per the sample proportion, margin of error, and required confidence level.

Calculate sample size with our free calculator and explore practical examples and formulas in our guide to find the best sample size for your study.

Use this advanced sample size calculator to calculate the sample size required for a one-sample statistic, or for differences between two proportions or means (two independent samples).

This sample size calculator helps you determine the optimal sample size needed for your statistical tests. It provides comprehensive power analysis with visual charts showing the relationship between …

When you survey a sample of the population, you don't know that you've found the correct answer, but you do know that there's a 95% chance that you're within the margin of error of the correct answer. …

Calculate the required sample size for your statistical study based on confidence level, margin of error, and population parameters.

Easily calculate your required sample size with our Sample Size Calculator. Fast, accurate, and perfect for surveys and research planning.

Instantly calculate the ideal sample size for your survey. Ensure statistically significant results by balancing your population, confidence level, and margin of error with our precision tool.

Jan 9, 2025 · If you are a clinical researcher trying to determine how many subjects to include in your study or you have another question related to sample size or power calculations, we developed this …