Free calculators for the mechanics and fluids problems that come up in design reviews and on the shop floor. Each one works in SI or US units, shows its intermediate steps, cites the published formula it uses, and has a worked example you can check by hand.
All of the math runs in your browser from closed-form textbook equations, and every result shows the steps that produced it. Each page lists its formulas with the reference they come from, the assumptions behind them, and the mistakes that most often give a wrong answer.
They are for checking and learning, not for signing off a design. Real parts have imperfections, connections that are not ideal, and code requirements that a closed-form formula does not capture. For the theory behind them, see the engineering fundamentals lessons; for shop-floor lookups, see the free manufacturing tools.
Yes. They run in the browser with no sign-up, and nothing you enter is sent to a server.
Every calculator has an SI / US switch. SI uses N, m, mm and MPa; US customary uses lbf, in, ft and ksi or psi.
They are exact for the idealised model each page describes: the arithmetic is double precision and results are shown to four significant figures. The model is usually the limit, so read the assumptions on each page.
They are useful for checking an answer you have worked yourself. Each page shows the method step by step so you can see where a hand calculation went wrong.
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