About StatCompute
Sixty-two statistics calculators that explain their answers, built on the principle that a number without an interpretation is half a result.
StatCompute is a set of 62 statistics calculators, built and maintained by ZW Studio LLC. Every tool on the site does its arithmetic in your browser: there is no server-side computation, no account, and nothing you type is uploaded or stored.
Why it exists
Search for almost any statistical test and you find two kinds of page. There are academic tools — often excellent, often a bare form with no explanation, sometimes unchanged since 2009. And there are general calculator sites, which cover thousands of unrelated topics and treat a t-test the same way they treat a tip calculator.
Neither tells you what the number means. That is the gap this site is built for. Every calculator here shows the formula it used, the arithmetic that produced the answer, a worked example with real numbers, and — the part that matters most — a plain reading of what the result does and does not support. A p-value of 0.03 does not mean your hypothesis is 97% likely to be true, and a page that hands you 0.03 without saying so has done half the job.
How it is built
The site is static HTML. There is no database and no application server; every page is a file, and the statistics run as JavaScript in your browser. That is a deliberate constraint rather than a limitation: it makes the site fast, it makes it work offline once loaded, and it means the sensitive column of numbers you paste into a calculator is not uploaded to us.
The numerical engine is written from scratch rather than assembled from a library, so that its accuracy can be stated rather than assumed. Every function is checked against R, the reference implementation used across academia and industry. The methodology page describes what is verified, how, and where the known limits are.
Corrections
If a number here is wrong, that is the most important thing anyone can tell us, and it will be fixed and the fix noted. Write to support@zwstudiollc.com with the calculator, the inputs and what you expected. The same address takes suggestions for tools that are missing.
Who runs it
StatCompute is operated by ZW Studio LLC, which is the company responsible for the site and for the answers on it. The site is free to use and is funded by advertising; see the privacy page for what that means for your data, and the terms for the limits of what these tools are for.