This project was supported by the National Center for Advancing Translational Sciences, National Institutes of Health, through UCSF-CTSI Grant Numbers UL1 TR000004 and UL1 TR001872. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH.

Please cite this site wherever used in published work:

Kohn MA, Senyak J. Sample Size Calculators [website]. UCSF CTSI. 9 January 2025. Available at https://www.sample-size.net/ [Accessed 26 April 2025]

Software utilities developed by Michael Kohn. Programming and site development by Josh Senyak at Quicksilver Consulting. Thanks to Mike Jarrett at quesgen.com for an early version of this site. Graphic design by Emanuel Heim Design.

This site was last updated on January 9, 2025.