The *Sample Size Calculator (web)* consists of:

- Means
- Single mean
- Two-mean comparison (independent)
- Two-mean comparison (paired) and standard deviation of difference
- Two-mean comparison (repeated measures)
- Proportions
- Single proportion
- Two-proportion comparison (independent)
- Two-proportion comparison (paired) [McNemar's test]
- Sensitivity and specificity
- Pearson's correlation
- Reliability
- Structural Equation Modeling
- Structural Equation Modeling by RMSEA (general)
- Confirmatory factor analysis by RMSEA
- Confirmatory factor analysis by CFI
- Confirmatory factor analysis by CFI (advanced)
- Misc: Calculate degrees of freedom, Calculate noncentrality parameter
- Animal study

Please view a short tutorial on sample size calculation using this web-based calculator.

This web version of the calculator started out as a project to convert the spreadsheet version into the version using JavaScript. Nowadays, the web version has more features than the spreadsheet version, for example, sample size calculators for confidence interval of *Pearson's correlation*, *Intraclass correlation coefficient*, *kappa coefficient* and *Cronbach's alpha coefficient*. It also includes the sample size calculator for animal study. New features are constantly added over time.

APA: Arifin, W. N. (). Sample size calculator (web). Retrieved from http://wnarifin.github.io

Vancouver: Arifin WN. Sample size calculator (web) [Internet]. [cited ]. Available from: http://wnarifin.github.io

Sample Size Calculator by Wan Nor Arifin is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

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© Wan Nor Arifin 2017-
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