✦ Research & Data Analysis

Research & Data Analysis Calculators

Support research and data analysis with calculators for sample size, confidence intervals, descriptive statistics, correlation, regression and hypothesis testing. Choose the method and assumptions that fit your research question and data structure. Statistical calculations can be misleading when assumptions are violated, so document your method and consult a qualified statistician for high-impact analysis.

25 calculatorsFree toolsGlobal research reference

Research Design & Sample Size

6 tools

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Sample Size Calculator — Single Proportion

Estimate sample size for a population proportion.

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Sample Size Calculator — Single Mean

Estimate sample size for a population mean.

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Sample Size Calculator — Two Proportions

Estimate sample size for comparing two proportions.

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Sample Size Calculator — Two Means

Estimate sample size for comparing two independent means.

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Power Analysis Calculator

Estimate statistical power from sample size and effect assumptions.

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Margin of Error Calculator

Calculate the margin of error for a research estimate.

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Descriptive Statistics

5 tools

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Mean, Median & Mode Calculator

Calculate the main measures of central tendency.

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Standard Deviation Calculator

Calculate sample or population standard deviation.

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Variance Calculator

Calculate sample or population variance.

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Quartile & IQR Calculator

Calculate quartiles and the interquartile range.

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Coefficient of Variation Calculator

Measure relative variability as a percentage.

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Confidence & Estimation

4 tools

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Confidence Interval for a Mean

Calculate a confidence interval for a population mean.

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Confidence Interval for a Proportion

Calculate a confidence interval for a population proportion.

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Confidence Interval — Difference of Means

Estimate the interval for the difference between two means.

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Confidence Interval — Difference of Proportions

Estimate the interval for the difference between two proportions.

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Correlation & Regression

5 tools

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Pearson Correlation Calculator

Calculate Pearson's correlation coefficient from paired data.

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Spearman Rank Correlation Calculator

Calculate rank correlation for paired observations.

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Simple Linear Regression Calculator

Calculate slope, intercept, fitted equation and R².

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Regression Prediction Calculator

Calculate predicted values and residuals from a regression equation.

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Coefficient of Determination Calculator

Calculate R² from explained and total variation.

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Hypothesis Testing & Research Effects

5 tools

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One-Sample Mean Test Calculator

Test a sample mean against a specified reference value.

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Two-Sample Mean Test Calculator

Compare two independent sample means.

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Proportion Test Calculator

Test a population proportion against a reference value.

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Effect Size Calculator

Calculate standardized research effect size measures.

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Z-Score & P-Value Calculator

Convert a z-score to a one- or two-tailed p-value.

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Research reference: These calculators are provided for statistical and research reference purposes. Results depend on the selected statistical method, assumptions, input data and study design. Always verify the method and assumptions appropriate to your research before using a result in formal analysis.