Power
Sample size per group
Sample size in group 2
Allocation ratio n1:n2 :
Drop-out rate
Calculate
Press the Calculate button to calculate the sample size.
Calculate Sample size Power (output decimal places: )
Advanced Unequal sample sizes Account for drop-outs Bonferroni correction
Probability in group 1
Probability in group 2
Test Pearson's Chi-squared test (pooled variance) Wald test (per-group variance estimates) Continuity correction