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.
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.
Sobel Test Calculator
Test whether the indirect effect in mediation analysis is statistically significant. Compare Sobel, Aroian, and Goodman tests with APA-ready citation.
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.
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.
AI Tools
Statistical Output Interpreter
Coming SoonPaste your SPSS, AMOS, or Excel output and get plain-language interpretation with APA-formatted results.
Planners
Methodology Planner
Coming SoonAnswer a few questions about your research and get recommended statistical tests, sample size guidance, and a methodology roadmap.