Sample Size & Power

PASS software provides sample size tools for over 650 statistical test and confidence interval scenarios. 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 has become 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

Choosing A Procedure

Enter The Values

Ready to Use Output

  • Obtaining A Sample Size
  • Choosing A Procedure
  • Enter The Values
  • Ready to Use Output

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"I really love this version of NCSS and as teacher and researcher in a medical field I can say there aren't many things I miss in it... The help system is another strong feature; the transformations interface is one of my favorites as well."

Dr. Adrian Buzea

"Your [PASS] routines are flexible and easy to use and your customer service and support is A-double-plus."

Nayak Polissar, PhD