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PCB Trace Width

IPC-2221 trace width from current and allowed temperature rise, with drop, loss and reverse lookup

Copper
Layer
Minimum width
1.367 mm
53.82 mil · 0.035 mm copper
Cross-section
74.162 mil²
Use at least
1.4 mm
Resistance
0.01872 Ω
Voltage drop
56.17 mV
Loss
168.5 mW
53.82 mil
Reverse: how much current fits a given width
→2.392 A

Based on the IPC-2221 curve fit: A = (I / (k · ΔT^0.44))^(1/0.725) with k = 0.048 for outer layers and 0.024 for inner ones. This is the minimum that meets the rise, before process margin — leave another 20%–50% on the board, and check IPC-2152 for high-current or high-reliability work.