Free, accurate, and educational electronics tools — built by engineers, for engineers.
Numerical Calculator was created by a small team of engineers and educators who were tired of switching between scattered formulas, clunky spreadsheets, and calculators that give an answer without showing how it was reached. We set out to build a single, reliable home for the everyday calculations people reach for again and again — across electronics, health, and energy.
Every tool in our suite pairs an instant numeric result with a live visual — a circuit schematic, a waveform, a body or savings chart, or a colour-coded diagram — so you not only get the value you need but also understand the relationship behind it. Each page includes the underlying formulas, worked examples, and reference tables, so it doubles as a learning resource.
Results update in real time as you type — based on standard engineering equations and IPC references.
Live diagrams and waveforms make abstract concepts concrete and intuitive.
Everything runs in your browser. No sign-up, no tracking, and it works offline once loaded.
We believe good engineering tools should be free, fast, and genuinely educational. Our mission is to remove friction from routine calculations so you can spend more time designing, building, and learning — and less time hunting for the right formula.
Have a suggestion for a new calculator or an improvement? We'd love to hear from you on our Contact page.