PCB Trace Width Calculator
Calculate the minimum copper trace width for a given current, per IPC-2221.
Result
0.3 mm
Width: 11.826 mil (16.296 mil²)
Usage examples
Sizing a power trace for a current-hungry circuit
Find the minimum copper width needed to carry a motor driver or power supply's current without overheating the board.
Checking whether an existing trace is wide enough
Enter a trace's width to see the maximum current it can safely carry at a given temperature rise.
Comparing outer vs. inner layer requirements
See how much wider an internal trace needs to be than an external one for the same current, since inner layers dissipate heat less effectively.
Frequently asked questions
Is my input sent to a server?
No. All calculations happen entirely in your browser.
Is this based on IPC-2221 or IPC-2152?
This uses the IPC-2221 simplified formula, the same one used by virtually every online PCB trace width calculator. The newer IPC-2152 standard relies on complex empirical thermal charts without a simple formula, so it isn't implemented here.
Why do different calculators give slightly different results?
The IPC-2221 formula is empirical, and small differences in rounding or copper-thickness assumptions between tools can shift the result by a few percent. Treat the output as a solid starting point, not an exact guarantee.
What temperature rise should I use?
10°C is a common conservative default for general-purpose boards. Use a lower value for temperature-sensitive designs, or check current IPC-2221 margin guidance for critical applications.