PCB Via Current Calculator

Estimate the current carrying capacity of a PCB via based on its dimensions and allowed temperature rise.

mm
µm
mm
°C

Current Capacity

2.97 A

Cross-Section73.0 mils²
Via Resistance22.75 mΩ

Current Capacity vs Via Outer Diameter

PCB Via Current Capacity

Approach

A via is a hollow copper cylinder. Its cross-section is:

A = pi x D x t_plating

Apply the IPC-2221 trace formula to this cross-section to estimate current capacity. For high current, use multiple vias in parallel.

Example Calculation

0.6 mm diameter via, 25 um plating, 1.6 mm board, 10C rise.

  1. 01Circumference = pi x 0.6 / 0.0254 = 74.2 mils
  2. 02Plating = 25 / 25.4 = 0.984 mils
  3. 03Area = 74.2 x 0.984 = 73.0 mils^2
  4. 04Current = 0.048 x 10^0.44 x 73^0.725 = ~2.8 A

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