Release notes
25 September 2026
Calculation engine updated to 1.18.3. Saved work is recomputed, and any change is flagged when you open it.
- Charts on Logic Power, Trace Width, Junction Temperature and Trace Inductance match the answers beside them.
- Units read plainly: Ω/sq, ppm/°C, °C/mV, dB/in, and ratios as 5.3:1.
- A Board profile button on every calculator it fills, and a Fab profile button where fab limits apply.
- Shorter labels, with the detail behind a ? beside each field.
- Parameter sweep: every step is drawn and named as in its table, on linear and log axes.
- Worst-case corners: sampled parts stay inside their tolerance.
24 September 2026
Calculation engine updated to 1.18.1. Saved work is recomputed, and any change is flagged when you open it.
- Three calculators: Transient Thermal Impedance, PDN Target Impedance, and AC Resistance, Skin Effect & Trace Loss.
- Every calculator judges its headline answer against a stated limit, or says why no verdict applies.
- Saved work that the current engine answers differently is marked Answer changed in Your work, with a link to what changed.
- Recent can be cleared, or switched off, in Your work.
- The About page counts calculators the same way as the rest of the site.
20 September 2026
- Plans. The calculators, verdicts and equations stay free for ever, with no account. Pro adds version history, parameter sweeps, worst-case corners, compare, full exports and unlimited signed reports, and every new account gets 14 days of Pro with no card.
- Parameter sweep: vary one input over a range and see the answer and verdict at every step, as a table and a curve, with CSV export.
- Compare two saved calculations side by side, with every difference marked.
- Version history: every edit to a saved calculation is kept.
- Pro features show a preview with a small Pro mark, never inside a result. If a plan ends, nothing is deleted or locked.
19 September 2026
- Save without an account: Ctrl-S keeps the calculation on this device, offline too, with a title, project and notes. Sign in later and it joins your account.
- Continue with these values: links under the results carry your numbers into the next calculator.
- Board profile: enter copper weight, thickness, dielectric, ambient and junction limit once, in Your work, and every calculator that asks for them fills them in.
- Recent, at the top of the calculator list: your last computations, each a link that reproduces it.
- Your work shows how much of your plan is used, filters by tag, and offers undo when you delete.
8 September 2026
Calculation engine updated to 1.8.1. Saved work is recomputed, and any change is flagged when you open it.
- Show working under the answer on the ten most-used calculators: the equation with your numbers in it.
- The headline answer stays in view until the result scrolls into view, at every width.
- An empty number field shows the shorthand it accepts, such as 4k7, 100n and 3V3.
- 3V3 reads as 3.3 V, just as 4k7 reads as 4.7 kΩ.
- A comma reads as a decimal point: 2,5 is 2.5 and 4,7k is 4.7 kΩ. Grouped thousands still work, as in 1,000.5, and an ambiguous value is flagged rather than guessed.
- Areas and volumes print in a clear unit, such as 25500 µm² or 0.5 mm³.
- Every calculator marks one headline answer, with the values that drive the next decision beside it.
7 September 2026
Calculation engine updated to 1.7.0. Saved work is recomputed, and any change is flagged when you open it.
- Wire Gauge & Voltage Drop: the AWG a run needs for its current and drop, or what a chosen gauge does.
- Crystal Load Capacitance: the C1 = C2 pair for a crystal’s C_L, and the ppm error of the pair you have.
- Via Stub & Back-drill: the stub’s quarter-wave resonance against your data rate, and the longest stub that stays clear of it.
- Trace Inductance & di/dt: partial and loop inductance of a trace, and the voltage a current step produces.
- Via & Pad Geometry: annular ring after drill registration, aspect ratio and clearance against your fab’s capability, and the smallest pad that passes.
- Copy results on every calculator: inputs, answers, verdicts and the link, ready for design notes and reviews.
- Saved calculations can be pinned to the top of your work and carry a note.
- On a phone the headline answer stays in view while you edit inputs, and a calculator page prints as a clean document.
- Numbers in preset chips and option lists read correctly on Arabic pages.
19 August 2026
Calculation engine updated to 1.5.0. Saved work is recomputed, and any change is flagged when you open it.
- The impedance calculator also solves in reverse: give a target impedance and it finds the trace width, for every line type.
- Fabrication tolerances on w, h and ε_r give worst-case minimum and maximum impedance.
- The cross-section has its own panel, and delay is behind a toggle.
- Chart cursors read plain numbers, such as 0.20 mm, and move in finer steps.
18 August 2026
Calculation engine updated to 1.4.0. Saved work is recomputed, and any change is flagged when you open it.
- The impedance calculator covers six line types: surface and embedded microstrip, symmetric stripline, edge-coupled differential microstrip and stripline, and grounded coplanar waveguide.
- It now uses the Hammerstad-Jensen and Cohn/Wadell models. Saved impedance numbers shift by a few percent, and the page explains the change when you open them.
16 August 2026
Calculation engine updated to 1.3.0. Saved work is recomputed, and any change is flagged when you open it.
- The Voltage Divider takes its tolerance from the series you pick, for example ±1 % for E96.
- Report a problem, in the footer of every page, with no account needed.
- The consulting page has a form: pick what you need and describe the work.
- A Most popular shelf at the top of the calculator index.
- Saved calculations show their inputs, stored answer and verdict in the list.
12 August 2026
- Charts draw as soon as the page opens.
- The MOSFET loss split is a chart, so the three losses compare at a glance.
- An account menu in the header: your projects, saved work and sign-out.
- Less text on every calculator. The equations stay in view, and the longer discussion is behind More detail.
- A What’s new note after each release.
11 August 2026
- A three-state theme control: light, dark, or follow your system.
- A retuned light theme and one type scale.
- Every verification address printed on a report opens its verification page.
- Privacy and Terms rewritten in plain words.
10 August 2026
Calculation engine updated to 1.3.0. Saved work is recomputed, and any change is flagged when you open it.
- Fields the calculator works out for you are read-only on every calculator.
- Equations are properly typeset, so fractions and roots stretch to fit.
- Redrawn charts, with sub-decade gridlines on logarithmic axes.
Engine record
What each engine release changed, and its effect on saved work.
Show the engine record
1.18.3 25 September 2026
Units read plainly: Ω/sq, ppm/°C, °C/mV, dB/in, mm/ns, W/(m·K), and ratios as 5.3:1. Reference lines on the divider and filter charts use series colours.
Effect on saved work: None, except an LDO with the input at or below the output: its thermal current limit now reads as a dash, and below the output its dissipation reads not regulating and its other thermal answers as dashes.
1.18.2 24 September 2026
Charts on Logic Power, Trace Width, Junction Temperature and Trace Inductance match the answers beside them.
Effect on saved work: None. Saved numbers are unchanged.
1.18.1 24 September 2026
The About page counts the 36 calculators, as the rest of the site does.
Effect on saved work: None.
1.18.0 22 September 2026
Every Fundamentals calculator states whether its answer carries a verdict. Ohm’s Law with all four values leads with the dissipation, and resistor synthesis offers the best stocked combination.
Effect on saved work: A saved Ohm’s Law calculation with all four values leads with the dissipation. A saved synthesis may offer a different, stocked combination. No other number moves.
1.17.0 22 September 2026
Power & Regulators: four calculators judge their headline answer, Battery Life states why it has no verdict, and two optional inputs are added.
Effect on saved work: Saved calculations gain a verdict or its reason. No number moves.
1.16.0 22 September 2026
LED Series Resistor, I2C Pull-up Sizing and Op-Amp Gain & Bandwidth judge their headline answer. Voltage Divider states why it has no verdict.
Effect on saved work: Saved calculations gain a verdict or its reason. No number moves.
1.15.0 22 September 2026
Crystal Load Capacitance judges its answer against the capacitance budget you enter.
Effect on saved work: A saved Crystal Load calculation between the budget and twice it reads Fail. No number moves.
1.14.0 22 September 2026
Junction Temperature and Thermal Network judge every mode they offer.
Effect on saved work: Saved calculations in these modes gain a verdict. No number moves.
1.13.2 22 September 2026
An answer is coloured only when it carries a verdict.
Effect on saved work: Eight answers show no colour. No number moves.
1.13.1 22 September 2026
A verdict is shown only when the answer and its limit can both be computed.
Effect on saved work: A saved calculation with an empty field may show no verdict. No number moves.
1.13.0 22 September 2026
Trace Width judges its answer in every solving mode.
Effect on saved work: A saved calculation in a solving mode shows its stored value and a verdict. No number moves.
1.12.1 22 September 2026
Three answers that have no limit to meet say so in place of a verdict.
Effect on saved work: A saved Controlled Impedance calculation with a tolerance shows two answers without colour. No number moves.
1.12.0 22 September 2026
Three headline answers show the verdict their page computes.
Effect on saved work: Saved calculations on these three show a verdict. No number moves.
1.11.5 21 September 2026
PDN Target Impedance names the resonance behind its peak.
Effect on saved work: None. The note beside the peak reads differently.
1.11.4 21 September 2026
A table row that cannot be read is named on the page.
Effect on saved work: No number moves. A saved calculation with such a row says so when opened.
1.11.3 21 September 2026
Junction Temperature and Logic Power cite their source in full.
Effect on saved work: None. The source line reads differently.
1.11.2 21 September 2026
An answer outside its method’s valid range reads Unverified, with the range and the source beside it.
Effect on saved work: No number moves. A saved calculation outside its method’s range opens as Unverified.
1.11.1 21 September 2026
A zero in a field the answer divides by is refused with a message.
Effect on saved work: None.
1.11.0 21 September 2026
New calculator: AC Resistance, Skin Effect & Trace Loss.
Effect on saved work: None.
1.10.0 21 September 2026
New calculator: PDN Target Impedance.
Effect on saved work: None.
1.9.0 21 September 2026
New calculator: Transient Thermal Impedance.
Effect on saved work: None. A saved Controlled Impedance calculation shows its answer without a ± band.
1.8.1 8 September 2026
3V3 reads as 3.3 V, as 4k7 reads as 4.7 k.
Effect on saved work: None, unless a saved value holds a V in place of its decimal point.
1.8.0 8 September 2026
A comma in a typed value is a decimal separator: 2,5 is 2.5.
Effect on saved work: A saved value typed with a comma reads as a decimal, and the page marks any answer that moved.
1.7.0 7 September 2026
New calculators: Via Stub & Back-drill, Trace Inductance & di/dt, and Via & Pad Geometry.
Effect on saved work: None.
1.6.0 7 September 2026
New calculators: Wire Gauge & Voltage Drop, and Crystal Load Capacitance.
Effect on saved work: None.
1.5.0 19 August 2026
Controlled Impedance solves for the geometry and bounds it with tolerances.
Effect on saved work: None. Delay figures show with their switch on.
1.4.0 18 August 2026
Controlled Impedance covers six line types, with the models field solvers use.
Effect on saved work: Numbers move: the default FR-4 microstrip reads 48.9 Ω, where it read 50.5 Ω, in line with a field solver.
1.3.0 16 August 2026
The Voltage Divider takes its resistor tolerance from the selected E-series.
Effect on saved work: The worst-case tolerance spread follows the series. Headline answers are unchanged.
1.1.0 5 August 2026
Clearance takes a voltage between two IPC-2221B bands into the band above, as the standard intends.
Effect on saved work: A saved clearance at a voltage between two bands may show a different spacing.
1.0.0 5 August 2026
First release: 30 calculators.
Effect on saved work: None.