Sample Size Calculator
Two-sample t-Test Paired t-Test Analysis of variance Wilcoxon Test Single proportion Chi-squared Test Fisher's exact Test McNemar's Test Logrank Test Correlation Test
Sample size calculator
Version 1.061


Input and calculation

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Press the Calculate button to calculate the sample size.





Number of events for a two-sample logrank test

The required number of events and the power for the logrank test are calculated according to Schoenfeld's formula, see [Schoenfeld, D. (1981). The asymptotic properties of nonparametric tests for comparing survival distributions. Biometrika, 68(1), 316-319.] and [Schoenfeld, D. A. (1983). Sample-size formula for the proportional-hazards regression model. Biometrics, 499-503.]

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