Sample Size Calculator

Calculate required sample sizes for surveys, experiments, and research studies

Instructions

1.Select calculation type (Mean, Proportion, or Group Comparison)
2.Enter the required parameters for your study
3.Specify confidence level or power requirements
4.Click “Calculate Sample Size” to get results

Effect Sizes

Small: d = 0.2
Medium: d = 0.5
Large: d = 0.8

Tips

• Use p = 0.5 for proportions when you want the maximum sample size

• 80% power is the standard minimum for most studies

• Consider adding 10-20% to account for dropouts

• Larger effect sizes require smaller sample sizes