Please enter all required values.
RESULTS
Input Parameters Specification
Trace WidthPCB copper track width. Wider traces reduce resistance because cross-sectional area increases, which helps in low-loss power routing and high-current PCB design.
Trace LengthTotal conductor path length. Longer PCB traces increase copper resistance and can create extra voltage drop in DC rails, LED drivers, regulators and power boards.
Trace ThicknessCopper thickness in oz/ft², mil, cm, mm, µm or inch. Thicker copper lowers trace resistance because the current path has more cross-sectional area.
TemperatureCopper resistance rises with temperature using the copper temperature coefficient. Hot PCB traces normally show higher resistance than room-temperature traces.
Practical Operational Examples
PCB Power Trace
Estimate voltage drop risk by calculating trace resistance for high-current copper tracks in SMPS boards, motor drivers, LED strips, relay boards and battery-powered PCB layouts.
Thermal Design
Use operating temperature to estimate how copper resistance changes in real board conditions, especially near MOSFETs, regulators, transformers and high-current connectors.
Prototype Check
Before final PCB manufacturing, compare different trace widths and copper thickness values to reduce heat generation and improve current-carrying performance.
Repair & Troubleshooting
When a PCB track burns or drops voltage under load, this calculator helps estimate whether the copper path is too narrow, too long or too hot for the current.
Diagrams & Theory
PCB trace resistance depends on copper resistivity, trace length, trace width, copper thickness and operating temperature. The diagram shows the trace dimensions used in the calculation. A wider or thicker copper trace lowers resistance, while a longer or hotter trace increases resistance.
Formulas & Mathematical Logic
Step 1: Convert width, length and thickness to centimeters using selected unit multipliers.
Step 2: Convert temperature to Celsius. °C stays same, K becomes K - 273.15, °F becomes 100 / 180 × (°F - 32).
Step 3: Copper resistivity constant = 17 × 10^-7 Ω·cm.
Step 4: Copper temperature coefficient = 0.0039 per °C.
Step 5: Cross-sectional area effect = width × thickness. Larger area lowers PCB trace resistance.
Step 6: Resistance = resistivity × length / (width × thickness) × (1 + coefficient × (temperature - 25)).
Step 7: Practical meaning: long and thin PCB traces create more copper resistance, while wider and thicker traces reduce voltage drop and heat.
Step-by-Step Example
Example: trace width = 50 mil, trace length = 2 inch, trace thickness = 1 mil, temperature = 25 °C.
The calculator first converts the width, length and copper thickness into centimeters.
Temperature remains 25 °C because the selected unit is already Celsius.
Copper resistivity is applied as 17 × 10^-7 Ω·cm.
The copper path area is calculated from trace width × thickness.
The final resistance result shows the estimated PCB copper trace resistance in ohms.
How to Use This Calculator
Enter the PCB trace width and select mil, cm, mm, µm or inch.
Enter the trace length based on the real current path on the PCB.
Enter copper thickness. For common PCB copper weight, use the oz/ft² option.
Enter the operating temperature and select °C, K or °F.
Click Calculate to get trace resistance and converted Celsius temperature.
Use the result to compare trace width, copper thickness and thermal impact before final PCB layout.
About This Calculator
Estimate copper resistance in PCB traces before layout problems appear.
The CalcBoy Trace Resistance Calculator helps calculate PCB copper trace resistance using trace width, trace length, copper thickness and operating temperature.
In PCB design, a copper trace is not a perfect conductor. It behaves like a small resistor, and that resistance becomes important when the board carries high current or uses very low supply voltage. A narrow trace in a 5 V regulator output, LED driver, motor controller or battery charging board can cause voltage drop, extra heating and unstable operation. This calculator gives a quick way to estimate that resistance before the PCB is manufactured.
The calculation is useful for printed circuit board design, power electronics, embedded hardware, SMPS layouts, battery-powered devices, automotive electronics and repair work. You can compare different trace widths, board copper thickness values and operating temperatures to see how the copper path changes. This is especially helpful when choosing between 1 oz copper, thicker copper, wider routing or a polygon pour for current-heavy nets.
Temperature is included because copper resistance increases when the board gets hot. A trace that looks safe at room temperature may show higher resistance near MOSFETs, power resistors, regulators or transformers. By entering a realistic operating temperature, the calculator gives a more practical estimate for real PCB conditions.
Best UsePCB trace resistance checks for power traces, copper tracks and high-current board routing.
Supported InputsTrace width, length, copper thickness and temperature with common PCB units.
Helpful ForSMPS boards, LED drivers, motor drivers, battery circuits and embedded electronics.
Design ReminderWider and thicker traces reduce resistance, voltage drop and copper heating.
Tip: For high-current PCB tracks, resistance is only one part of the design. Also check temperature rise, copper area, via current, connector rating and voltage drop at the load.
Frequently Asked Questions
What is PCB trace resistance?
PCB trace resistance is the electrical resistance of a copper track on a printed circuit board. It depends on trace length, width, copper thickness and temperature.
Does a wider PCB trace reduce resistance?
Yes. A wider trace increases copper cross-sectional area, which lowers resistance and reduces voltage drop.
Why does copper thickness matter?
Thicker copper gives more conductor area. This reduces trace resistance and helps carry higher current with less heating.
Why is temperature included?
Copper resistance increases as temperature rises. Hot PCB areas near power parts can have higher trace resistance than room-temperature calculations.
Can this calculator be used for high-current PCB design?
Yes, it helps estimate resistance, but high-current PCB design should also consider trace temperature rise, copper pours, vias, connectors and safety margin.
What unit should I use for PCB trace width?
Mil is commonly used in PCB layout, but you can also enter cm, mm, µm or inch depending on your design data.
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