PCB Via Parasitics Calculator
A plated-through-hole via has series inductance (from its height and barrel diameter) and shunt capacitance (from the antipad clearance in the surrounding ground planes). Together they set a self-resonant frequency that limits high-speed and RF performance. For die/package bond wires, see the Bond Wire calculator.
Equations & Parameters ▸
\(L_{via}=0.2\,h\ln\!\left(\tfrac{4h}{d}\right)\text{nH}\quad C_{via}=\tfrac{1.41\,\varepsilon_r\,h}{\ln(D/d)}\text{pF}\quad f_{SRF}=\tfrac{1}{2\pi\sqrt{LC}}\)
| h | Via height (mm) = substrate thickness the via passes through. |
| d | Via (drill / barrel) diameter (mm). |
| D | Antipad diameter (mm) — the clearance hole in the ground plane. Larger D → less capacitance. |
| εᵣ | Substrate dielectric constant. FR4 ≈ 4.4. |
| f_SRF | Self-resonant frequency of the L–C pair; keep operation well below it. |
Reference: IPC-2141A §4.3 (via capacitance); standard cylindrical-conductor via inductance model
Inputs
mm
substrate thicknessmm
drill diametermm
clearance hole in ground planeFR4 ≈ 4.4
Results
Via Parasitics
Inductance, L_via—
Capacitance, C_via—
Self-resonant frequency—
Diagram