Jun 30, 2025 · To calculate sample size, first find the population size, or number of people taking your study, and margin of error, which is the amount of error you'll allow in your results.

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

The Cochran formula allows you to calculate an ideal sample size given a desired level of precision, desired confidence level, and the estimated proportion of the attribute present in the population.

To determine an appropriate sample size n for estimating proportions, the equation below can be solved, where W represents the desired width of the confidence interval. The resulting sample size formula, …

May 15, 2025 · Learn how to calculate survey sample sizes by exploring margin of error, confidence levels, population variability, and practical formulas.

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.

Jul 23, 2025 · The formula to calculate the sample size for a survey or study depends on several factors, including the desired confidence level, the margin of error (confidence interval), the population size, …