Research Tools
Free, accurate statistical calculators for psychology, research methods, and academic work. All calculations happen locally in your browser.
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Statistical Calculators
Reliability
Cronbach's Alpha Calculator
Calculate Cronbach's alpha to assess the internal consistency reliability of a scale or questionnaire.
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Effect Size
Cohen's d Calculator
Calculate Cohen's d effect size for comparing two independent group means, with Hedges' g correction.
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Study Design
Sample Size Calculator
Calculate the required sample size for estimating a population proportion with a given confidence level and margin of error.
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More Research Tools Coming Soon
We're building a comprehensive suite of free statistical tools for researchers and students.
Pearson Correlation CalculatorCorrelation
Spearman Correlation CalculatorCorrelation
Independent t-Test CalculatorHypothesis Testing
Paired t-Test CalculatorHypothesis Testing
One-Way ANOVA CalculatorHypothesis Testing
Chi-Square Test CalculatorHypothesis Testing
Confidence Interval CalculatorEstimation
Statistical Power CalculatorStudy Design
Z-Score CalculatorDescriptive Statistics
Standard Error CalculatorDescriptive Statistics
APA Table GeneratorReporting
Likert Scale ScoringData Preparation
Reverse Scoring CalculatorData Preparation
Regression CalculatorModeling