### Power and Sample Size | Free Online Calculators

Power and Sample Size .com. Free, Online, Easy-to-Use Power and Sample Size Calculators. no java applets, plugins, registration, or downloads ... just free . Go Straight to the Calculators » Power? What Power? Statistical power is a fundamental consideration when designing research experiments. It goes hand-in-hand with sample size. The formulas that our calculators use come from clinical ...