ResiCalc: Resistor Networks

ResiCalc turns any resistor network into a clear answer — and shows you exactly how it got there. From high-school series/parallel problems to Wheatstone bridges and Y–Δ transforms in circuit theory, to voltage dividers and power checks at the bench, ResiCalc solves it and explains it. DRAW IT, SOLVE IT • Tap to place nodes, drag to connect resistors; 0 Ω is an ideal wire • Grid snapping, undo/redo, pinch to zoom and pan • Pick any two nodes as terminals — the equivalent resistance updates live • IEC rectangle or ANSI zig-zag resistor symbols STEP-BY-STEP SOLUTIONS • Merges wires, removes dangling and floating branches, combines series and parallel • Detects balanced bridges; otherwise applies Y–Δ (star–mesh) transforms • Every step comes with an explanation, the worked formula and a diagram • Great for homework checks, exam revision and teaching FULL CIRCUIT ANALYSIS • Apply a voltage or current source across the terminals • Node voltages plus voltage, current, power and load ratio for every resistor • Current arrows, node voltages and a power heat map directly on the canvas • Set power ratings and get overload warnings ENGINEERING-GRADE TOLERANCE • Exact worst-case bounds • Monte Carlo histogram and yield • Sensitivity ranking shows which resistor deserves a precision part RESISTOR TOOLBOX • 4/5/6-band color code, both directions • E3–E192 standard values • Combination finder: hit any value with 2–3 standard resistors • Voltage divider designer • Ohm's law and quick series/parallel calculators MORE • Multiple projects and 11 classic templates (resistor cube, R-2R ladder, 3×3 grid…) • Export PNG schematics and multi-page PDF reports • English and Chinese, Dark Mode • Fully offline, no data collection, no ads FREE AND PRO Drawing circuits, equivalent resistance, templates and the core tools are free. ResiCalc Pro is a one-time purchase (no subscription) that unlocks full analysis, all solution steps, tolerance analysis, the combination finder, divider designer, unlimited projects and PDF reports.