Stripline Calculator
Stripline is a flat conductor sandwiched symmetrically between two ground planes. It is a fully shielded TEM medium — no dispersion, no radiation, lower loss than microstrip. Common in multilayer PCBs for RF routing and controlled-impedance backplanes.
Equations & Parameters ▸
\(Z_0 = \dfrac{60}{\sqrt{\varepsilon_r}}\ln\!\left(\dfrac{4b}{0.67\pi w_{\rm eff}(0.8+t/w)}\right)\)
| w | Trace width (mm). |
| b | Total substrate height (mm) — distance between the two ground planes. |
| t | Trace thickness (mm). |
| εᵣ | Dielectric constant of the filling material. FR4 ≈ 4.4. |
| Z₀ | Characteristic impedance. The trace is centred between the planes. |
| vₚ | Phase velocity = c/√εᵣ. Stripline is fully embedded so vₚ has no air correction. |
Physical constants used
| c | Speed of light = 2.998×10⁸ m/s |
| µ₀ | Permeability of free space = 4π×10⁻⁷ H/m ≈ 1.2566×10⁻⁶ H/m |
| ε₀ | Permittivity of free space = 8.854×10⁻¹² F/m |
Inputs
mm
mm
total gap between ground planesmm
1 oz Cu = 0.035 mmFR4≈4.4, Rogers4003≈3.55
Results
Electrical
Characteristic impedance, Z₀—
Phase velocity, vₚ—
Capacitance/length—
Inductance/length—
Diagram