Hi, and Welcome! We're currently rebuilding this site. All the same calculators will be here + about 200 more! ×

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The all-new

Power and sample size .com

Beta

This is the All-New Power and Sample Size .com. We're currently working hard to deliver some AWESOME new tools! Keep checking back, we have great things to deploy here in the near future!

We currently have 35 calculators, but we have a total of about 160 in the works!

Power and Sample Size

A quickstart guide

List of Features

Calculators Home Page

Current features: Calculators Index

Upcoming features:

  • Filtered search
  • Text search
  • AI-assisted search

Calculator Page

  • Downloadable, interactive Graph
  • Downloadable, interactive Table
  • Form that supports comma-separated lists, ranges, fractions, and numerical expressions
  • Summary Statement suitable for executive summaries, scientific protocols, manuscripts, and other professional documents
  • Citation
  • Title
  • Description
  • References (some calculators)

Upcoming features:

  • Easily save and share your work with a URL that takes you back to your settings

Calculator Form

  • Select which metric to calculate (e.g. Sample Size, Power, Confidence Interval)
  • Enter numerical values as:
    • A single whole or decimal number
    • A comma-separated list of numbers like
      • 2, 3, 4
    • Fractions like
      • 1/2, 1.5/3, 0.1/22, 1/0.22
    • Mathematical expressions:
      • pi, exp(1), sqrt(2), 1/3 + 0.2, sin(pi/4) (also cos() and tan()), e, e**2, tau, log(2) (natural logarithm)
    • A range of numbers like:
      • 2-3
      • 2..3
    • A range of numbers with a whole-number or decimal step like:
      • 2-5:1, 0.05-0.15:0.05
      • 2..5:1, 0.05..0.15:0.05
      • 2-5:0.5
      • 2..5:0.5
  • A comma-separated mix of any of these

Upcoming features:

  • Visual aid and warnings on syntax
  • Automatic boundary restrictions, e.g. $0 \lt alpha \lt 1$

Calculator Graph

  • Download: click the download button or the camera icon
  • Zoom, pan, hover, reset scale
  • Select the y-axis and x-axis variables
  • Select a group variable to show multiple lines for inputs having multiple values

Calculator Table

  • Download: click the download button
  • Navigate pages with buttons at the bottom of the table
  • Sort columns, select number of rows to display, search feature

All pages

  • Select light or dark theme
  • Download the page's source code
  • Suggest edits to a page or add comments on the website's GitHub repository