PASS software provides sample size tools for over 740 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. Get to know PASS by downloading a free trial, viewing the video to the right, or exploring this website. PASS comes complete with integrated documentation and PhD statistician support. PASS has been fine-tuned for over 20 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.
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.
Finding the sample size procedure is easy using the drop-down menu, the procedure search, or the category tree. Watch a short video to learn how to select your desired procedure in PASS.
The sample size procedure tools are easy to use and have built-in help messages for every option.
Enlarge the infographic to see the descriptions of the ways that PASS helps you to enter the proper values in a sample size procedure tool. You can also watch this video to see an example of using a procedure window in PASS.
When a PASS procedure is run, the sample size results and corresponding plots are displayed in the output window. The sample size or power curves can be clicked to be shown in a separate window for viewing or saving.
Navigation of the output is easy with the output navigation tree. The format of the output makes it easy to be viewed, copied and pasted, or saved. Multiple output runs can be sent to the output gallery for saving or for comparing sample size analyses.
450 MHz or faster processor
32-bit (x86) or 64-bit (x64) processor
256 MB (512 MB recommended)
Windows XP with Service Pack 2 or higher
Windows 8 and 8.1
Windows 10 or later
Windows Server 2003
Windows Server 2008
Windows Server 2008 R2
Windows Server 2012
Windows Server 2012 R2 or later
Administrative rights required during installation only
Third Party Software：
Microsoft .NET 3.5 SP1 (included with PASS CD, comes pre-installed with Windows 7 and Windows Server 2008 R2, feature activation required on Windows 8, 8.1, 10 and Windows Server 2012 and 2012 R2) Microsoft Windows Installer 3.1 or higher
Adobe Reader® 7 or higher (required for the Help System only)
Hard Disk Space：
120 MB for PASS (plus space for Microsoft .NET 3.5 SP1 if not already installed)
Any Windows-compatible inkjet or laser printer
A Windows emulator (such as Parallels) is required to run PASS 15 on a Mac.