PCB Trace Calculator
Calculate minimum PCB trace width or maximum current capacity using the IPC-2221 standard.
Free & unlimitedWorks offline
Mode
External layer
k = 0.048Minimum trace width
0.300 mm
11.83 mil
Nearest standard width
12 mil (0.305 mm)
Resistance
81.990 mΩ
V drop
81.990 mV
Power loss
81.990 mW
Internal layer
k = 0.024Minimum trace width
0.781 mm
30.77 mil
Nearest standard width
40 mil (1.016 mm)
Resistance
31.517 mΩ
V drop
31.517 mV
Power loss
31.517 mW
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About this tool
- 1
Enter current requirement
Input the maximum current the trace needs to carry in amps.
- 2
Set trace parameters
Enter the copper weight (oz/ft²), acceptable temperature rise, and trace length.
- 3
Choose layer type
Select whether the trace is on an external (outer) layer or internal layer - internal traces need to be wider.
- 4
View results
Get the minimum trace width, resistance, and voltage drop per the IPC-2221 standard.
- Internal layers dissipate heat less effectively, so internal traces need to be 2-3x wider than external traces for the same current.
- Keep temperature rise below 10°C for most applications; high-reliability designs may require even less.
- For high-current paths, consider using copper pours or multiple vias instead of narrow traces.
- IPC-2221 standard-compliant trace width calculations
- Supports both external and internal copper layers
- Calculates trace resistance and voltage drop over length
- Temperature rise estimation for thermal analysis
- Common copper weight presets (0.5oz, 1oz, 2oz)
- Designing power delivery traces on a PCB for high-current loads
- Verifying trace widths meet IPC standards before sending a board to fabrication
- Estimating voltage drop in long PCB traces for sensitive analog circuits
- Sizing traces for motor driver boards or battery charging circuits