Hey there, fellow hardware engineer, PCB enthusiast, or just someone who’s tired of doing back‑of‑the‑envelope math for the hundredth time. 👋
Let me be real – designing a board is fun until you have to calculate trace impedance, figure out how much current a via can handle, or guess the parasitic capacitance between two signal lines. You could grab a textbook, dig up formulas, and punch numbers into a calculator. Or… you could use the 12 free tools I’ve put together.
All of them live on my website, and they’re completely free. No sign‑up, no spam. Just fast, reliable calculations that follow industry standards (IPC, IEEE, you name it).
Here’s the full list – each one solves a real pain point I’ve run into over the years.
Need to know the DC resistance of a PCB spiral coil or a wire‑wound inductor? This one does it in seconds. Enter turns, shape (circular or rectangular), material (copper, aluminum, gold, silver, or custom), and for PCB coils: trace width + copper thickness; for wire coils: wire diameter. Boom – resistance value, plus the full breakdown of ρ·L/A.
When you’ll use it: Winding your own inductors, designing wireless charging coils, or checking losses in a custom solenoid.
2 oz, 4 oz, even 6 oz copper? Normal trace width formulas break down. This tool is built for heavy copper power boards. Enter your target current, temp rise (10 °C, 20 °C, etc.), and layer (external or internal). It tells you the minimum trace width you need – IPC‑2221 compliant.
Real‑life use: Battery management systems, motor drivers, or any board where you’re pushing 20 A+ through copper.
Think of this as your “design rule check” assistant. Three calculators in one:
Why I love it: One page to quickly check if my layout will pass a safety review.
Hot components need proper cooling. This tool helps you figure out how many thermal vias you need under a pad and what pad size gives you lower junction temperature. Enter device power, max ambient temp, and desired RθJA – it suggests a thermal via array.
Where it shines: LED PCBs, voltage regulators, and any high‑dissipation SMD part.
Designing a buck or boost converter? Stop guessing the inductor and output capacitor. This tool takes your input/output voltage, switching frequency, and current ripple requirement. It recommends inductance, saturation current, output capacitance, and even sense resistor for current‑mode control.
Saved my bacon: When I had to size a 12 V‑to‑5 V 3 A converter quickly, this gave me a great starting point.
Crosstalk driving you crazy? This calculator estimates trace‑to‑trace (coplanar) capacitance and plane‑to‑plane capacitance. Choose your dielectric material (FR‑4, Rogers, etc.) or enter a custom εr. Length, thickness, spacing – get the capacitance in pF or fF.
Perfect for: High‑speed digital (think DDR or Ethernet) and EMI troubleshooting.
Need a 50 Ω microstrip or a 100 Ω differential pair? This tool handles single‑ended microstrip, stripline, and edge‑coupled differential pairs. Enter stackup (H, W, T, εr) and it returns characteristic impedance, effective dielectric constant, and propagation delay (ps/mm and ps/inch).
Why it’s a lifesaver: Instead of messing with polar or complex field solvers, I can dial in my stackup in 30 seconds.
Lead inductance of a TO‑220 pin? Via inductance through a 1.6 mm board? Self‑inductance of a PCB trace? Use this tool. Three modes: round pin/lead, rectangular trace, and through‑hole via. Enter dimensions and get inductance in nH/µH.
Where it matters: Power integrity (L di/dt spikes), high‑frequency switching, and return path planning.
Vias aren’t just holes – they add capacitance and inductance. This tool helps you choose the right pad diameter and anti‑pad clearance for signal integrity and manufacturability. Enter via drill size, pad diameter, anti‑pad clearance, and board thickness. It shows you via capacitance, inductance, and stub resonance.
When I use it: Designing high‑speed backplanes or RF boards where every via matters.
Power Distribution Network design can be intimidating. This calculator takes your target ripple voltage, transient current, and switching frequency. It calculates the target impedance (Ztarget) and suggests bulk and high‑frequency decoupling capacitor values (with ESL/ESR taken into account). Also identifies potential resonant peaks.
Great for: FPGA or processor power rails where you need to keep impedance low across a wide frequency range.
A Swiss army knife for RF folks. Three modules:
Why it’s handy: I can quickly sanity‑check a PA output or a receiver sensitivity spec.
Need to match trace lengths for a bus (e.g., parallel DDR or SPI)? Enter the stackup (dielectric constant, height) and trace geometry – the tool gives you delay per millimeter or per inch. Then you can figure out how much longer one trace needs to be.
Real talk: Saved me from clock skew problems more than once.
Just head to my website – all 12 tools are sitting in the root directory, ready to use. No login, no paywall. Bookmark them, share them with your team, or use them on your phone while working at the lab bench.
👉 Try them now: https//www.pcbsky.com/tools/
And if you ever get stuck or have a weird PCB question – email me at sales@pcbsky.com. I’ll help you out for free. Seriously. No strings attached.
These calculators are my way of giving back to the engineering community. I’ve spent countless nights debugging layout issues that a simple tool could have prevented. Now you can skip the pain.
Happy designing!
– Your friendly PCB tool nerd 🛠️
