Via Current & Thermal Calculator
Vias carrying real current — power planes, high-current signal transitions — need the same IPC-2221 scrutiny as traces. This calculator rates a plated via barrel's current capacity and thermal rise from its drill size, plating thickness, and barrel length, applying the internal-layer derate IPC-2221 requires. Run it before committing to a via count on a power stitching pattern, or while diagnosing an unexpectedly hot via on a returned board.
Via Current & Thermal Rating
Plated barrel, IPC-2221 internal derate
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Current / via
0.95 A
Current × 1
0.95 A
Barrel area
39.56 mil²
Barrel R(dc)
1.08 mΩ
θ / via
162.8 K/W
θ × 1 parallel
162.8 K/W
Thermal figure is conduction through the copper barrel only; unfilled vias carry no meaningful heat in the air column. For thermal pads, stitch 4–9 vias of 0.3 mm on a 1.0–1.2 mm pitch.