Stripline Impedance Calculator
Characteristic impedance of an embedded stripline trace from geometry and εr — the inner-layer companion to the microstrip tool.
Stripline gives ~15 % slower propagation than microstrip (the field is entirely inside the dielectric) but far better EMI containment and no impedance shift from solder mask. For the same Z₀, a stripline trace must be narrower than its microstrip equivalent — check your fabricator's minimum trace width before committing to a thin stack-up.
Stripline Impedance Calculator computes the characteristic impedance of an inner-layer trace sandwiched between two reference planes — free, instant and private in your browser. Designers routing high-speed signals on inner layers for shielding and EMI control use it to skip the datasheet algebra: type your numbers, read the answer with the substituted formula shown step by step, and share an exact permalink of the calculation.
About Stripline Impedance Calculator
Stripline Impedance Calculator computes the characteristic impedance of an inner-layer trace sandwiched between two reference planes using the standard engineering relation: Z₀ = 60/√εr · ln(1.9b/(0.8w+t)) (IPC-2141A symmetric stripline). Worked live: a 0.15 mm trace centred in 0.5 mm of FR-4 gives roughly 50 Ω. The result recalculates on every keystroke, the worked-example panel shows your numbers substituted into the formula, and the Copy permalink button encodes the inputs in the URL so a colleague opens exactly your calculation. Everything runs client-side — nothing you type leaves your device.
How to use Stripline Impedance Calculator
- 1Enter your values — the tool starts with realistic defaults for this exact use case, so the worked example is meaningful immediately.
- 2Read the live result and the worked-example panel, which substitutes your numbers into the formula step by step.
- 3Adjust any input to compare scenarios, then use Copy result or Copy permalink to share the calculation.
Why use Stripline Impedance Calculator?
- ✓Implements the real formula — Z₀ = 60/√εr · ln(1.9b/(0.8w+t)) (IPC-2141A symmetric stripline) — with the substitution shown, not a black box
- ✓Built for designers routing high-speed signals on inner layers for shielding and EMI control
- ✓Copy result and permalink buttons — share the exact calculation in a README, forum answer or design review
- ✓100% free, no sign-up, runs entirely in your browser (works offline once loaded)
Frequently asked questions
How do you calculate stripline impedance?+
The characteristic impedance of an inner-layer trace sandwiched between two reference planes follows Z₀ = 60/√εr · ln(1.9b/(0.8w+t)) (IPC-2141A symmetric stripline). For example, a 0.15 mm trace centred in 0.5 mm of FR-4 gives roughly 50 Ω. The calculator applies the same relation and shows the substituted arithmetic so you can verify every step.
Why are stripline traces narrower than microstrip for the same impedance?+
The trace is fully surrounded by dielectric (no air above), so the effective permittivity is higher and capacitance per length larger. The same Z₀ therefore needs a thinner, narrower line — typically 60–70 % of the microstrip width.
Is stripline better than microstrip for EMI?+
Yes for radiation: the two planes shield the trace, and its fields stay inside the board. The costs are tighter width tolerances, slower propagation (~half-speed of air) and the need for via transitions with nearby return-path stitching.
Is the Stripline Impedance Calculator free and private?+
Yes — completely free with no sign-up or usage limits, and it runs entirely in your browser: the values you enter are never uploaded or stored on a server.
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