PCB Current Calculator
Determine maximum current capacity for your PCB traces
PCB Current Calculator
Estimate how much current a PCB trace can carry on internal and external layers before final stackup and manufacturing review.
Precise Calculation
When to use this calculator
Use it when you already know the trace geometry and want to check whether the planned copper can safely carry the required current.
Compare internal and external layer current capacity before finalizing routing strategy, copper weight, and thermal assumptions.
Use the estimate to decide when to widen traces, increase copper thickness, or review the design with fabrication engineering.
Tool Features
Precise Calculation
Accurate current limits based on trace geometry and thermal constraints.
Safety First
Ensure your designs meet safety standards by verifying current handling capabilities.
Related resources & next steps
Estimate the minimum trace width you may need before validating how much current it can safely carry.
Extend current planning into via structures when power paths cross layers.
Review copper weight, manufacturability, and stackup decisions with fabrication support.
Send your routing assumptions and current targets to our engineering team for design review.
Frequently asked questions
Can I use this calculator as the final manufacturing value?
Use it as an engineering estimate, not a final fabrication rule. Final current capacity should be confirmed against actual copper thickness, stackup, airflow, adjacent copper, and manufacturing limits.
Why is internal layer current capacity lower than external layer capacity?
Internal traces dissipate heat less effectively because they are buried in the stackup. For the same copper geometry, internal layers usually carry less current than external layers.
What should I do if the estimate is too close to my target current?
Increase trace width, increase copper weight, reduce allowed temperature rise, or review the design with manufacturing engineering before release if the margin is too small.
Need help validating current capacity against your real PCB stackup?
If you are balancing current load, copper weight, thermal rise, and manufacturing limits, we can review your design and help turn the estimate into a manufacturable decision.