PCB trace width calculator
Compute the minimum trace width from current, temperature rise and copper thickness (IPC-2221).
A
°C
oz
- External layer
- 0.300 mm (11.8 mil)
- Internal layer
- 0.781 mm (30.8 mil)
Formula
A = (I / (k × ΔT^0.44))^(1/0.725) · W = A / (t × 1.378)
k = 0.048 for outer layers, 0.024 for inner layers. A 10 °C rise is a safe choice. Add margin: fabs rarely accept less than 0.15 mm.
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