Web-Based Tools

Comprehensive Set of Calculators
This site offers a lengthy list of calculators covering a wide array of statistical purposes. Includes over 600 links and almost 400 calculating pages!


Commonly-Used Calculators

Chart Builder


Difference of Proportions (Z-test)


Effect Size


Percent Change


Sample Size / Margin of Error

  • EZ-SRS-SS for Random Samples developed by Organizational Development (Excel 2007 version, Excel 2003 version)
    Sample size for proportions, means, and totals.
  • EZ-SRS-ME for Random Samples developed by Organizational Development (Excel 2007 version, Excel 2003 version).
    Margin of error for proportions, means, and totals. Reports both question-level and response category-level margin of errors for up to 8 response categories in a single survey question.
  • Calculator for Random Samples #1
    Sample size and margin of error for proportions (assumes proportion of 0.5 for most conservative estimate).
  • Calculator for Random Samples #2
    Sample size and margin of error for proportions (enter proportion for greater precision).


Statistical Power

Comments are closed.