About Free Statistics Tools
The statistics calculator is free, needs no sign-up and runs in your browser, so your numbers are never uploaded. Paste a list and it returns the mean, median, mode, range, variance, standard deviation, quartiles and outliers, with the calculation written out step by step.
It also gives a z-score and percentile for any value, a t-based confidence interval for the mean at 90%, 95% or 99%, and the Pearson correlation and least-squares line between two lists. Each of these has its own page, from the standard deviation calculator to the quartile and IQR calculator, and all of them open the same tool with the matching result outlined.
One switch matters more than any other: sample (divide by n - 1) or population (divide by n). It changes the variance, the standard deviation, the z-score and more, and the calculator lets you flip it and compare. These tools describe data. They do not run hypothesis tests, so there is no p-value, t-test, sample size or probability table.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial and no credit card. Ulkaa Tool does the work with your own device, so there is no server bill to pass on to you.
Do I need an account?
No. There is no sign-up and no login. Open the page and use it. An Ulkaa account is not needed for anything on this tool.
Does it run in my browser?
Yes. Numbers are processed by code running in your browser tab, on your own device.
Is my data uploaded?
No. Numbers are never sent to Ulkaa or to anyone else. You can check this yourself by watching the Network tab in your browser developer tools while you use the tool.
What is the difference between sample and population standard deviation?
The population version divides by n and the sample version divides by n - 1. Use the sample version when your numbers are a sample of a larger group. For 2, 4, 4, 4, 5, 5, 7, 9 they are 2 and 2.1381.
Which statistics can I calculate here?
Mean, median, mode, range, variance, standard deviation, standard error, quartiles, IQR, outliers, skewness, kurtosis, z-scores, percentiles, a confidence interval for the mean, Pearson correlation and a simple linear regression line.
Can I run a t-test or get a p-value?
No. These tools summarise data. They do not run hypothesis tests or calculate p-values, sample sizes or probabilities.
How should I separate the numbers?
Use commas, semicolons, spaces or new lines, and a dot for decimals. Text that is not a number is skipped, so check the count of values read.