Shapiro–Wilk normality calculator
Paste one sample and compare the statistic, p-value and QQ plot.
Normal QQ plot
Inspect departures from the line.
Ordered quantiles
| Order | Theoretical | Observed |
|---|---|---|
| Fill in the fields above — the result is computed on this page. | ||
How do I use this page?
- Paste values.
- Inspect the statistic and plot.
What this page does not do: The p-value is an approximation and does not validate independence or the sampling plan.
Further reading
Theory — what is the Shapiro–Wilk test?
The Shapiro–Wilk test checks whether a single sample could come from a normal distribution. The calculation relies on expected normal scores and an explicitly described approximation used within the Shapiro–Wilk family of methods. The calculator presents the test statistic alongside the p-value and a QQ plot, making it easier to judge deviations from normality. A small p-value means the observed sample is hard to reconcile with the fitted normal distribution.
Frequently asked questions
What does a small p-value mean?
See also
A/B test calculator
Compare two proportions in an A/B test. Calculate conversion rates, difference, uplift, z score, p value and c
A/B test planning — sample size, MDE and duration
Plan a two-proportion experiment, estimate detectable effect and traffic duration.
ACF and PACF autocorrelation calculator
Calculate ACF and PACF across time-series lags. Review the chart, reference bounds and coefficient table.