Sample Size & Power Calculation
for Successful Clinical Trials

In 2016, 93% of organizations with FDA approved clinical trials used nQuery for sample size calculation


15 Ways To Reduce
Sample Size In Clinical Trials


Common Clinical Trial Design &
Sample Size Calculation Mistakes to Avoid

20 Years


nQuery celebrates its 20th birthday in 2016. Over those 20 years, nQuery has earned the position as  the world's most trusted sample size calculator & power analysis software for clinical trials.

50,000 Users


Our community is growing every day and is now standing at 50,000 users worldwide at over 6,000 commercial, academic and government organizations.

1000's of Successful Trials


Regulatory Approval drives nQuery forward. Recognized by FDA, EMA & other agencies for being robust and accurate, it has already been deployed as the sample size calculator in 1000's of successful clinical trials. 

Calculate quickly & easily...


  • No coding necessary, nQuery's intuitive easy to use interface allows you to calculate power & sample size quickly and accurately

  • Easily conduct a variety of “What-If” scenarios to align your final sample size choice with your scientific and budgetary requirements

  • 50,000 users worldwide - join the club today

... with complete confidence...


  • Complete suite of 100's of fully validated sample size procedures

  • Partnering with Big Pharma for 20 years, we know every scenario so you can calculate power & sample size with complete confidence

  • The most trusted sample size calculator & power analysis software, proven over 1000’s of successful clinical trials

... for regulatory approval.


  • nQuery was designed specifically for regulatory approval

  • Our sample size statement generator automatically outputs your sample size statement in the correct language & format for submission to regulatory agencies and peer-reviewed publications

  • 93% of organizations with clinical trials approved in 2016 used nQuery to calculate power and sample size

Generator ›


We work extensively with our customers and global regulatory agencies to ensure nQuery always meets regulatory requirements and guidelines globally. FDA, EMA, PMDA and other regulatory agencies are active users of nQuery, so their reviewers are very familiar with nQuery sample size & power analysis calculations and can assess your submission quickly & easily.

Guidelines learn More ›Statement generator ›

Check out our library of over 20 case studies and examples that showcase how to conduct sample size calculations and power analysis using nQuery. 

All examples use real-life clinical trial data from studies published by leading pharmaceutical companies, including GSK, Pfizer, Amgen, etc., and are classified by both therapeutic area and statistical method so you can quickly and easily select the example most relevant to your research area and requirements.

Explore All Examples ›


I have been a user of nQuery software since the late 90's for sample size calculations in clinical trials, and for the last 14 years nQuery has been a standard product in the Boehringer-Ingelheim toolkit

Andy Lawton., Boehringer-Ingelheim

Reduce your risk and calculate sample size for a successful clinical trial 

Buy online now or request of trial nQuery


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