About Reuven
Reuven Engineering Tools is a free suite of 269 engineering calculators spanning 17 disciplines — structural, geotechnical, concrete, HVAC, electrical, hydraulics, transportation, building physics, and more. It exists because the everyday calculations of design work deserve tools that show their formulas, cite their standards, and work instantly in the browser without accounts, paywalls, or spreadsheet archaeology.
How the Calculators Are Built
Every calculator follows the same discipline. It implements published methods from recognized codes and references — Eurocodes, ACI, AISC, ASHRAE, NEC, AASHTO, and the standards each page cites — rather than ad-hoc approximations. The formulas used are printed on the page, so you can check the math by hand. Each tool ships with a worked example, and its calculation engine is covered by an automated test suite that pins results to independently derived values, so a code change that shifts an answer fails the build.
Calculations run in your browser. Some tools save preferences locally or let you explicitly share settings in a link and export results. The privacy policy explains those choices and optional usage analytics.
Accuracy & Limitations
These calculators are aids for preliminary design, checking, and learning — not a replacement for engineering judgment or for the governing code in your jurisdiction. Standards differ between countries and editions, and a method valid for one situation may not cover yours. Verify results against project-specific requirements before using them in final documentation. The terms of use spell this out in full.
When we find an error — or you report one — we fix the calculation, add a regression test so it stays fixed, and update the page. Corrections are the most valuable mail we get.
Who Is Behind It
Reuven is an independent project, built and maintained by a small team with backgrounds in engineering and software. The project started with a single window-fabrication calculator and grew tool by tool as colleagues asked for the next one. The calculators are free to use. We are applying for advertising support; ad serving is currently disabled.
Get in Touch
Found a wrong result, a standard we should support, or a calculator we should build next? Email [email protected] or use the contact page. We read everything.