PCB Trace Width Calculator
Calculate PCB trace width based on current, temperature rise, and copper thickness. Essential for PCB design and power routing.
PCB Trace Width Calculator
Typical: 10-20°C (default: 10°C)
Common: 0.5, 1, 2 oz (default: 1 oz)
Copper Thickness Reference
| Thickness | Mils | Micrometers (μm) | Common Use |
|---|---|---|---|
| 0.5 oz | 0.685 | 17.4 | Low current, signal traces |
| 1 oz | 1.37 | 34.8 | Standard, most common |
| 2 oz | 2.74 | 69.6 | Power traces, high current |
| 3 oz | 4.11 | 104.4 | High power applications |
| 4 oz | 5.48 | 139.2 | Very high current |
Formulas
IPC-2221 Trace Width:
w = (I / (k × ΔT^0.44))^(1/0.725)
Where: w = width (mils), I = current (A), k = 0.048 (outer) or 0.024 (inner), ΔT = temp rise (°C)
Resistance:
R = (ρ × L) / (w × t)
Where: ρ = resistivity (1.68×10⁻⁸ Ω·m for copper), L = length, w = width, t = thickness
Voltage Drop:
V = I × R
Power Dissipation:
P = I × V_drop
Note: The calculator uses IPC-2221 standard formulas. Outer layers can dissipate heat better than inner layers, allowing narrower traces for the same current. Always add safety margin (20-30%) for production tolerances.