Max Current Calculator

trace current diagram


Trace Width
Trace Thickness
Temperature Rise

Output ⊕

Trace Resistance: 
0.117 Ω

External Trace (outer layer)

Max Current: 
0.466 Amps
Voltage Drop: 
0.0548 Volts
Power Dissipation: 
0.0255 Watts

Internal Trace (inner layer)

Max Current: 
0.233 Amps
Voltage Drop: 
0.0274 Volts
Power Dissipation: 
0.00638 Watts

View Notes

Calculation Notes

This tool calculates the maximum current a trace can carry. Internal trace values are the results for a trace within a multilayer, although outer traces that are potted or insulated should also use internal values. Outer trace values are the results for a trace that is exposed to the air, normally on the top or bottom layers of a circuit.

Factors that influence the current calculation include:-

  • Trace width (w)
  • Trace thickness (t)
  • Temperature rise (ΔT)
  • Trace length (l)

i_{ext} \approx 0.028 \times {\Delta T}^{0.46} \times w^{0.76} \times t^{0.54}\; (external trace max current)

i_{int} \approx 0.014 \times {\Delta T}^{0.46} \times w^{0.76} \times t^{0.54}\; (internal trace max current)

  • Electrical Circuit Theory and Technology (ISBN 978-1-85617-770-2)
  • Douglas Brooks, "Temperature Rise in PCB Traces", 1998

Disclaimer: The information and this tool are provided with no liability of any kind whatsoever, use at your own risk.

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