Tools
Calculators we use on our own bench
Built because we needed them, published because they are useful. Every result is a shareable link, every tool shows the equation it uses, and none of them asks for an email address.
- No sign-up
- No cookies, no third parties
- The physics, explained
- Shareable results
Copper and current
Sizing conductors for the current they actually carry, and the heat that comes with it.
Trace width and current capacity
Width for a target current and temperature rise, with resistance, drop and dissipation. Live cross-section and a temp-rise curve.
Open the calculator IPC-2221BVia current and thermal vias
What one barrel carries, how many a current needs, and where a thermal via array stops paying back. Array drawn to scale.
Open the calculator OnderdonkTrace fusing current
What it takes to open a trace and how long it survives a fault, with the time-to-fuse curve and an honest note on why traces make poor fuses.
Open the calculator AWG / mm²Wire gauge and voltage drop
Both limits at once — current the wire can carry, and voltage that never reaches the far end. With bundle derating for harnesses.
Open the calculatorSignal integrity
Geometry that decides whether a high-speed interface works on the first spin.
Controlled impedance suite
Microstrip, stripline and coplanar waveguide, single-ended and differential — with real fabricator stack-ups that fill in the dielectric for you.
Open the calculator NEXT / FEXTCrosstalk estimator
Near-end and far-end coupling from your actual geometry, and whether the 3W rule is doing what you think on this stack-up.
Open the calculator Vendor-neutralStack-up builder
Assemble layers, get finished thickness, trace widths for your impedance targets on every signal layer, and a symmetry check so it will not bow.
Open the calculatorPower and thermal
The failure modes that present as "random" and are not.
Decoupling network designer
Target impedance plotted against frequency, showing the anti-resonance peaks that make a rail worse when you add the wrong capacitor.
Open the calculator Series RLCHot-plug inrush and LC ringing
What the rail does in the first microseconds after a live connection, with peak overshoot flagged against your capacitor rating.
Open the calculator θja / θjcJunction temperature and thermal chain
Die to ambient as a chain of resistances, drawn to scale so you can see which link is actually costing you the temperature.
Open the calculator Duty cycleBattery life estimator
Duty-cycle profile in, years out — with the self-discharge, converter losses and pulse limits that make real devices fall short.
Open the calculatorEveryday bench work
The small calculations that come up on every project and are worth not doing in your head.
Resistor divider and E-series solver
Searches every standard pair for the ratio you actually want, then shows what tolerance does to it. E12 through E192.
Open the calculator mil / mm / ozPCB units and PPM converter
Mils, millimetres, ounces of copper and microns — plus tempco drift, which usually dominates initial tolerance.
Open the calculator Altium / KiCad / EagleComponent library finder
One part number, every CAD library source and every distributor, correctly formed. Strips distributor suffixes and tells you what to check before you trust the model.
Open the calculator LoRaWANLoRa link budget
Whether the link closes, how much margin it has, and what each spreading factor costs you in airtime and battery.
Open the calculatorCompliance
The regulations that decide whether a product can be sold, and when they start applying.
EU Cyber Resilience Act scoper
Eight questions: whether the CRA applies to your product, which Annex III class it lands in, whether you can self-assess, and what you have to produce by when.
Open the calculator Crossover analysisModule or chip-down?
The crossover volume where designing the radio in stops costing more than buying it pre-certified. Sometimes the honest answer is "buy the module" — it says so.
Open the calculator EN 55032EMC failure triage
You failed at 143 MHz. Enter your clock list and it identifies which harmonic that is, how it is probably getting out, and where the limit line sits.
Open the calculator Pre-tapeoutDesign review checklist
Describe the board and get the pre-tapeout checklist we would run against it — filtered to what applies, ordered by what costs most to miss. Printable.
Open the calculatorSafety and mechanical
Where the standard, not the schematic, sets the dimension.
Creepage and clearance
Both standards at once, because where they disagree is the number that matters. Pollution degree, material group, altitude.
Open the calculator IPC-2223Rigid-flex bend radius
Minimum bend radius from copper thickness and stack-up, against outer-fiber strain limits for static and dynamic bends.
Open the calculatorWhat next
All 21 are live — everything we set out to build, plus the ones we only thought of once people started using them.
What gets built next should come from what people actually need rather than from a list we wrote ourselves. If there is a calculation you keep doing by hand, or one where every tool you can find gets it wrong, tell us — that is the useful signal, and we build those first.
A calculator gives you a starting number.
Getting a fabricator to hold it is the other half of the job. Send us the stack-up and the thermal environment, and we'll tell you what is actually achievable.