Projects

Save the inputs of every calculator for a board under one name, come back to them later, and export or import them as a project file. Everything stays in your browser.

Method, formulas and references

What a project holds

Every calculator keeps its inputs in its own web address, which is why any result can be shared as a link. A project is simply a named list of those states: the impedance geometry for a board, its loss setup, the regulator and thermal numbers, and so on, one entry per tool. Saving a tool again replaces its earlier entry, so a project always holds the current version.

Where it is stored

In your browser, on this device. Nothing is uploaded, there is no account and no server: the site has no database at all. That also means a project is only on the computer and browser where you made it, and clearing site data removes it.

Project files

Export writes a small JSON file holding the projects and your custom stackups, so it opens complete on another machine. Import merges a file into this browser; projects with a name that already exists are kept separately, so nothing is overwritten. Use a file to back up your work, move it between computers, or send a board setup to a colleague.

The format is plain JSON with a version number, so older files keep working when the site changes.

Related utilities tools

All calculators

Signal integrity

Impedance Calculator – Single-ended and differential microstrip, coated and embedded microstrip, stripline and coplanar lines, solved with a 2D field solver.
Propagation Delay, εeff & Timing – Propagation delay, length matching from skew, rise time to bandwidth, critical length and wavelength.
Trace Loss (Insertion Loss) Calculator – Insertion loss in dB/in and over the full length: conductor loss with copper roughness and dielectric loss from the field solver, with laminate Dk/Df across frequency.
Crosstalk Calculator – Near- and far-end crosstalk between parallel traces from the field solver, with a sweep over the spacing (3W rule check).
Differential Via – Via-pair differential impedance through the plane clearance from a 2D field solution, antipad sizing for a target, stub resonance and delay.
Via Stitching & Via Fence Spacing – Stitching and fence via pitch from the wavelength (λ/10, λ/20), via-grid cell resonance, leakage between vias and plane-pair cavity resonances.
Interface Design Rules – Impedance, skew, loss budget and length limits of PCIe, USB, Ethernet, HDMI, DDR and other interfaces, applied to a layer of your own stackup with the field solver.

Stackup

Stackup Advisor – Enter board thickness, layer count and impedance requirements; the field solver ranks every matching fab stackup and gives the trace widths.
Layer Stack Manager – 178 fab stackups from 2 to 12 layers, editable, with any signal layer sent to the impedance calculator.
PCB Laminate Materials (Dk / Df) – Datasheet Dk and Df of FR-4, low-loss and RF laminates (Isola, Panasonic, Rogers, Shengyi…) at any frequency, plus solder masks and copper foil roughness.

Thermal

Junction Temperature – Junction temperature from power and the thermal-resistance chain (θJA or θJC + θCS + θSA), and the maximum power for a Tj limit.
Thermal Via Array – Thermal resistance of a via array under a hot pad, with plugged or filled vias, and the temperature drop through the board.
Copper Area for Heat Spreading – How much copper a hot part needs: copper-pour thermal resistance by convection and radiation, junction temperature and the smallest pour for a Tj limit.

Power & conductors

Trace Width, Current & Temperature Rise – IPC-2221: width for a current, current for a width, or temperature rise of a trace, with resistance, voltage drop and loss.
Via Calculator – Via current capacity, resistance, thermal resistance, capacitance, inductance and rise-time impact.
Skin Effect & AC Resistance – Skin depth in copper and the AC resistance of a trace across frequency.
Fusing Current – Current that melts a trace in a given time (Onderdonk), for fault and surge analysis.
Wire Gauge & Voltage Drop – AWG diameter, area and resistance, cable voltage drop and loss, the smallest gauge for a drop limit, and Preece fusing current.
Conductor Spacing (IPC-2221) – Minimum electrical clearance between conductors from IPC-2221 Table 6-1: internal, external, coated, high altitude, assemblies.
Creepage & Clearance (IEC 60664-1) – Minimum clearance and creepage per IEC 60664-1: impulse voltage from mains and overvoltage category, pollution degree, CTI material group, reinforced insulation, altitude.

Power integrity

PDN Impedance Calculator – Target impedance, plane-pair capacitance, decoupling-capacitor resonance and the number of capacitors needed, with a log-log |Z|(f) plot.

Power supply

Buck Converter Calculator – Step-down converter power stage: duty cycle, inductor and ripple current, peak switch current, input and output capacitors (TI SLVA477B).
Boost Converter Calculator – Step-up converter power stage: duty cycle, inductor, peak switch current, maximum output current of the IC and output capacitor (TI SLVA372D).
LDO Regulator Power Dissipation – Linear regulator dissipation, junction temperature, efficiency and dropout headroom, with the maximum load for a Tj limit.
Feedback Resistor Divider – Standard-value R1/R2 for adjustable regulators: the best E12/E24/E96 pairs, output error, FB bias current and worst case with tolerance.

Components

Planar Spiral Inductor – Inductance of square, hexagonal, octagonal and circular PCB spirals (modified Wheeler and current-sheet models), with DC resistance and Q.
Through-Hole Padstack Calculator – Plated through-hole sizing per IPC-7251 / IPC-2221 / IPC-2222: hole, outer and inner pads, antipad, thermal relief and annular ring for levels A/B/C.
BGA Land Pattern – IPC-7351 land diameter for collapsing and non-collapsing BGA balls, with tolerance and courtyard, and escape-routing capacity between lands.

Electronics

Ohm's Law & Power – Enter any two of voltage, current, resistance and power to get the other two.
Reactance & LC Resonance – XL and XC at a frequency, LC resonance, the L or C for a target frequency, and series/parallel LC impedance with Q.
Crystal Load Capacitors & PPM – Crystal load capacitors with the nearest E12/E24 values and resulting CL, plus frequency error ↔ ppm and clock drift.
Resistor Tools – Voltage divider with best E12/E24/E96 pairs, LED series resistor with power rating, and series/parallel R, C and L.
Attenuator Pads – Matched Pi, T and bridged-T pads with the nearest standard values, their actual loss and return loss, and resistor power.

Utilities

Projects – Save the inputs of every calculator for a board under one name, reopen them later, and export or import them as a project file.
Unit Converter – Length, copper weight, temperature, power (dBm/W/V) and frequency/wavelength.
Reference Charts – Drill sizes (number, letter, fractional, metric), ISO metric and Unified threads with tap and clearance drills, and the AWG wire table.