Trace width for current capacity in PCB Design - Cell-by-Cell Formula Trace

Sample Data

This data shows current in Amps, allowed temperature rise in Celsius, copper thickness in ounces, and the trace width in mm to be calculated for PCB design.

Cell	Value
A1	Current (Amps)
B1	Temperature Rise (°C)
C1	Copper Thickness (oz)
D1	Trace Width (mm)
A2	5
B2	10
C2	1
D2
A3	10
B3	20
C3	2
D3

Formula Trace

D2 = 0.024 * (A2 ^ 0.44) * (B2 ^ 0.725) / C2

Step 1: A2 ^ 0.44

Step 2: B2 ^ 0.725

Step 3: 0.024 * 2.095 * 5.316

Step 4: 0.2673 / C2

Step 5: D2 = 0.2673

Cell Reference Map

   A      B       C       D
1 Current TempRise Copper  TraceWidth
2  5      10      1       ->
3 10      20      2       

Arrows show D2 depends on A2, B2, C2

Trace width in D2 is calculated using current in A2, temperature rise in B2, and copper thickness in C2.

Result

   A      B       C       D
1 Current TempRise Copper  TraceWidth
2  5      10      1       0.2673
3 10      20      2       

D2 shows the calculated trace width in mm for the given parameters.

The calculated trace width for the first row is about 0.2673 mm, showing how wide the PCB trace should be to safely carry 5 Amps with 10°C temperature rise and 1 oz copper.

Sheet Trace Quiz - 3 Questions

What is the result of raising the current 5 Amps to the power 0.44?

A 2.095

B 5.316

C 0.2673

D 0.024

Key Result

Trace width = constant * (Current ^ 0.44) * (TemperatureRise ^ 0.725) / CopperThickness