PASS software provides sample size tools for over 1200 statistical test and confidence interval scenarios - more than double the capability of any other sample size software. Each tool has been carefully validated with published articles and/or texts.

PASS has been fine-tuned for over 25 years, and is now the leading sample size software choice for clinical trial, pharmaceutical, and other medical research. It has also become a mainstay in all other fields where sample size calculation or evaluation is needed.

Obtaining A Sample Size In PASS
In PASS, you can estimate the sample size for a statistical test or confidence interval in a few short steps. If you need guidance during any of the steps, PASS has excellent documentation, there are free training videos, and you can contact our team of PhD statisticians.