Tools

About these tools

There are more than 40 calculators, solvers and lookup tools here, and all of them are free. They are built to show their working: you can switch between metric and US units, see the formula and the steps behind every answer, share a link to your exact inputs, and print or save the result as a PDF.

Each tool page has a worked example that the calculator is tested against, notes on where the method stops being valid, and links to the guide pages that explain the theory. Members can also export results to CSV or Excel, and keep their own bookmarks and workspace.

Our calculators are for learning and first estimates, not a replacement for the standards and professionals your project needs. Read how we write and check our pages, or send us a correction.