Here are 9 methods you can use to calculate your sample size 01 — Cochran’s Formula Best for large populations requiring proportion estimates. Widely used in surveys, market research, and social science studies. 02 — Slovin’s Formula Simple and practical when the population size is known but variability data is unavailable. Common in student research and small-scale projects. 03 — Power Analysis Determines sample size using effect size, significance level, and statistical power. Essential in cli