Normality and Assumption Tests
Shapiro-wilk Test Statistical Calculator
Shapiro-Wilk Test Calculator test normality using Shapiro-Wilk. Use Shapiro-Wilk Test Calculator to validate raw numeric data, alpha and report method, n, w_statistic, p_value, alpha, decision with method-specific calculations, diagnostics, and interpretation. Use the tabbed test workspace below for data, variables, analysis, visualizations, results, interpretation and reporting.
Quick method summary
The Shapiro-Wilk Test Statistical Calculator calculates the named method using calculator-specific formulas and reports auditable results, warnings, and interpretation. It uses the calculator-specific formula and reports the intermediate values, final result, warnings, and interpretation.
Normality and Assumption Tests
Shapiro-Wilk Test Calculator
Test normality using Shapiro-Wilk. Use Shapiro-Wilk Test Calculator to validate raw numeric data, alpha and report method, n, w_statistic, p_value, alpha, decision with method-specific calculations, diagnostics, and interpretation.
Calculated result
Calculation method
Shapiro-Wilk W compares ordered observations with expected normal order statistics. Coefficients and the p-value transformation follow Royston AS R94 for sample sizes from 3 through 5000.
Formula
Shapiro-Wilk W compares ordered observations with expected normal order statistics. Coefficients and the p-value transformation follow Royston AS R94 for sample sizes from 3 through 5000.
Assumptions and limits
The selected sample, groups, residuals, or repeated-measure matrix must be the quantity whose assumption is being assessed. Results can be sensitive to sample size, rounding, ties, missingness, and extreme observations. Use the numerical test together with diagnostic plots and the robustness requirements of the planned analysis.
Formula review
Formula and independent control cases reviewed 2026-08-02; variable assumptions remain visible inputs.
Shapiro-Wilk Test Calculator method, assumptions and reporting guideComplete selected-test explanation, assumptions, formula and reporting details
Data Import and Variable Requirements
For the Shapiro-Wilk Test Statistical Calculator, upload or paste data, review the cleaning report, then select the outcome, group, subject, condition, or matrix roles required by Shapiro-Wilk Test Calculator. For Shapiro-Wilk Test Calculator, map Raw numeric data, Alpha from the cleaned browser-local table; every mapped variable remains editable before calculation, and the active dataset remains available while you work with this selected test and when you return to the Test Finder.
Uploaded files are processed locally in the browser. The cleaning report appears before variable selection, and the selected cleaned columns are mapped to this exact calculator rather than a generic fallback.
Shapiro-Wilk Test Calculator Workspace Features
- Dedicated Shapiro-Wilk Test Calculator variable mapping, calculation contract, result explanation, and diagnostics
- Manual inputs plus browser-local XLSX, CSV, or TSV analysis for this exact statistical method
- Auditable cleaning report before method-valid variable dropdowns are created
- Calculator-specific formulas, intermediate quantities, assumptions, warnings, and interpretation
- Responsive method-specific charts generated from the selected cleaned data
- Copy, result CSV, cleaned-data CSV, chart PNG, and result-only print controls
- Protected canonical URL, focused FAQs, and a dedicated selected-test workspace
About the Shapiro-Wilk Test Calculator
Test normality using Shapiro-Wilk. Use Shapiro-Wilk Test Calculator to validate raw numeric data, alpha and report method, n, w_statistic, p_value, alpha, decision with method-specific calculations, diagnostics, and interpretation. Assumption tests evaluate a named aspect of distribution shape, variance equality, or repeated-measures covariance structure.
When to Use the Shapiro-Wilk Test Calculator
Use the Shapiro-Wilk Test Statistical Calculator when your research question, variable types, and sampling or experimental design require shapiro-wilk test. Do not select it only because the data produce a convenient p-value or familiar output.
How the Shapiro-Wilk Test Calculator Works
Shapiro-Wilk W compares ordered observations with expected normal order statistics. Coefficients and the p-value transformation follow Royston AS R94 for sample sizes from 3 through 5000.
The calculation runs in the browser. Submitted values are validated for required numeric ranges, data shape, units and method-specific restrictions before results are shown.
Assumptions and Checks
- The selected sample, groups, residuals, or repeated-measure matrix must be the quantity whose assumption is being assessed.
- Results can be sensitive to sample size, rounding, ties, missingness, and extreme observations.
- Use the numerical test together with diagnostic plots and the robustness requirements of the planned analysis.
Required Inputs
- Raw numeric data (required)
- Alpha (required)
Results Reported
The result workspace shows the final answer and intermediate quantities needed to audit the calculation. Depending on the method, reported values include:
- Method
method - N
n - W Statistic
w_statistic - P Value
p_value - Alpha
alpha - Decision
decision - Coefficients
coefficients
Shapiro-Wilk Test Calculator Worked Example
Use the example data button to load a known sample, then calculate and review the statistic, p-value or estimate, and interpretation.
| Input | Example value |
|---|---|
| Raw numeric data | 1.2,2.1,2.8,3.4,4.0,4.7,5.3,5.9,6.4,7.1,7.8,8.2 |
| Alpha | 0.05 |
Verified Worked Result
The packaged automated fixture produces the following checked values from the example inputs. Display rounding can differ from the full-precision browser result.
| Result | Verified value |
|---|---|
| N | 12 |
| W Statistic | 0.96941402820227 |
| Test Statistic | 0.96941402820227 |
| P Value | 0.90456923557354 |
| Decision | Fail to reject normality |
| Coefficients 0 | 0.547433600953 |
| Coefficients 1 | 0.33257805885874 |
| Coefficients 2 | 0.2345433776271 |
How to Use This Workspace
- Confirm that the method matches the quantity, hypothesis, model or planning question you need to solve.
- Enter values with compatible units and the requested sample, group, matrix, count, date or option format.
- Use Example Data to inspect a valid input layout, or enter your own values and run the calculation.
- Review the result table, formula, substitutions, warnings and interpretation rather than relying only on the headline number.
- Copy, download or print the result when you need a reusable analysis record.
Understanding and Reporting the Result
Review Method, N, W Statistic, P Value, Alpha, Decision, and Coefficients. Use the displayed assumptions, warnings, and interpretation before reporting the result. In the Shapiro-Wilk Test Calculator result workspace, interpret method, n, w_statistic, p_value, alpha, decision together with the method assumptions, warning messages, confidence information, effect magnitude, and diagnostic plots shown for the selected variables.
Use plots and subject-matter judgment with p-values because assumption tests can have low power in small samples and excessive sensitivity in large samples.
Keep the entered values, units, selected options and any warning shown beside the result. For a hypothesis test, report the statistic, degrees of freedom where applicable, p-value, alpha level, effect size and decision. For an estimate or conversion, report the formula convention and final unit.
How to Report the Result
When reporting results from the Shapiro-Wilk Test Statistical Calculator, identify the design and software, state the valid sample size and exclusions, then report Method, N, W Statistic, P Value, Alpha, Decision, Coefficients. Include the selected alpha level, tail, coding, and assumption decisions when they apply. A reproducible Shapiro-Wilk Test Calculator report should identify the mapped variables, valid observations, exclusions or missing-data handling, selected options, principal outputs, uncertainty, diagnostics, and the practical conclusion supported by the analysis.
Accuracy and Limitations
The calculator keeps full browser precision during calculation and rounds only for display. Accuracy still depends on correct inputs and on whether the displayed model represents the real problem. Educational calculators cannot replace required professional review, current official rules, field measurements, laboratory methods or specialist statistical software where those are necessary.
Frequently Asked Questions
What does the Shapiro-Wilk Test Calculator calculate?
Test normality using Shapiro-Wilk. Use Shapiro-Wilk Test Calculator to validate raw numeric data, alpha and report method, n, w_statistic, p_value, alpha, decision with method-specific calculations, diagnostics, and interpretation.
Which formula does the Shapiro-Wilk Test Calculator use?
Shapiro-Wilk W compares ordered observations with expected normal order statistics. Coefficients and the p-value transformation follow Royston AS R94 for sample sizes from 3 through 5000.
When should I use the Shapiro-Wilk Test Statistical Calculator?
Use the Shapiro-Wilk Test Statistical Calculator when your research question, variable types, and sampling or experimental design require shapiro-wilk test. Do not select it only because the data produce a convenient p-value or familiar output.
What inputs does the Shapiro-Wilk Test Statistical Calculator require?
Upload or paste data, review the cleaning report, then select the outcome, group, subject, condition, or matrix roles required by Shapiro-Wilk Test Calculator.
What does the Shapiro-Wilk Test Statistical Calculator report?
Review Method, N, W Statistic, P Value, Alpha, Decision, and Coefficients. Use the displayed assumptions, warnings, and interpretation before reporting the result.
Can the Shapiro-Wilk Test Statistical Calculator analyze Excel or CSV data?
Yes. The file is cleaned locally in the browser, then method-valid variable dropdowns place the selected data into this exact calculator.