Statistics Tools

Free calculators and tools to help you with your thesis or dissertation. No signup required for basic usage.

Calculators

Cronbach's Alpha Calculator

Calculate Cronbach's alpha instantly. Paste your data, get reliability coefficient, item-total correlations, alpha-if-deleted analysis, and APA-ready citation.

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Sample Size Calculator

Calculate your required sample size using three methods: Yamane (1967), Cochran (1977), and Krejcie & Morgan (1970). Compare results side-by-side with APA citation.

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Sobel Test Calculator

Test whether the indirect effect in mediation analysis is statistically significant. Compare Sobel, Aroian, and Goodman tests with APA-ready citation.

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IOC Calculator

Calculate the Index of Objective Congruence (IOC) for content validity. Evaluate questionnaire items with expert ratings (+1/0/-1) and get APA-ready citation.

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Effect Size Calculator

Calculate Cohen's d, eta-squared, partial eta-squared, R-squared, odds ratio, and Cramér's V. Get magnitude interpretation with APA-ready citation.

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McDonald's Omega Calculator

The modern alternative to Cronbach's alpha. Paste your item scores and get ω, factor loadings, variance explained, and an APA-ready citation.

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AI Tools

Chapter 4 Interpreter

Upload your SPSS output PDF or paste text. Get thesis-ready APA-formatted results for Chapter 4 — reliability, descriptive, assumptions, and hypothesis testing.

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Planners

Methodology Planner

Coming Soon

Answer a few questions about your research and get recommended statistical tests, sample size guidance, and a methodology roadmap.