Sample Size Estimation

Introduction: In general, sample size calculation is conducted through a pre-study power analysis. Its purpose is to select an appropriate sample size in achieving a desired power for correctly detection of a pre-specified clinical meaningful difference at a given level of significance. This study/tool will provide statistical procedures for determination of sample size required not only for testing equality, but also for testing non-inferiority/superiority, equivalence (similarity), some survival analysis and phase II clinical trials designs that are commonly employed at various phases of clinical development. As a handful tool, it is very useful for clinical scientists and biostatisticians in the pharmaceutical industry, regulatory agencies, academia, and other researchers.

This program helps users to determine sample sizes and confidence intervals for a wide range of statistical techniques including means, proportions, survival analysis, phase II clinical trials, epidemiological studies and some general cases).





Survival Analysis

Phase II Clinical Trials

Epidemiological Studies

Confidence Intervals


1. Correlation Coefficient using z-transformation

2. Standard Normal Calculator