All You Need to Know About PCB Trace Width Calculation

A PCB trace width calculator is used to determine the PCB trace width with the help of IPC 2221 formulas. The trace width is an important consideration when designing a circuit board. In reality, to prevent shreds from damage caused by high temperatures, you should give them the appropriate thickness.

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when the current load exceeds the higher limit, the trace burns out or ruins the circuit board laminate. Long-term PCB damage may ensue as a result of this.

PCB traces are similar to cables that link nil-resistance parts together. Each PCB path, on the other hand, has its resistance, which is a crucial factor to consider when calculating PCB trace width.

You’ll need to know the resistance and current conduction potential to figure out what width to use.

It’s important to note that when the temperature rises, the trace width changes. The temperature difference between conducting current and not conducting current is referred to as the temperature rise. To look at it another way, subtract the operating temperature from the upper operational temperature to compute the temperature rise.

Calculating the trace width appears to take a lot of time and effort. However, you shouldn’t be worried anymore because the PCB calculator trace width tends to make the process a lot easier and more accurate

How do you figure out the PCB Trace Width Calculation?

It’s not enough to find the accessible circuit board trace or apply a basic strategy or operation to appropriately determine your trace resistance. To ensure that your circuit board traces switch on properly, you should identify your PCB traces and trace width. By establishing and greatly increasing your PCB trace width, you can lower the resistance of your circuit board traces.

What Should You Know About PCB Trace Width Calculation?

It’s far easier to locate a specific conductor than it is to determine the PCB Trace Width Calculation. This is since there are several elements to consider when calculating your circuit board’s trace width. For example, you should be aware of the maximum current and trace thickness that your PCB can withstand.

PCB Trace Spacing & Length:

You may need certain spacing and lengths in digital designs with high-speed communication to avoid cross-talk, coupling, and reflections. USB-based serial differential signals and RAM-based parallel differential signals are two common applications. In general, you may require a differential pair routing of 480Mbit/s or higher for USB 2.0. This is partly due to high-speed USB’s lower voltage and divergence, which puts the overall signal level further to the noise floor.

When routing high-speed USB lines, you need to consider three parameters: trace width, trace spacing, and trace length.

The most crucial of these three is to ensure that the two traces’ lengths are as close as feasible. As a general rule, if the traces are separated by more than 50 mils (for high-speed USB), the possibility of reflections grows considerably, thereby, resulting in poor communication. To attain 90 Ohm matched impedance, which is a typical standard for differential pair routing, you need to modify the width and spacing of the traces.

PCB Trace Width Formula:

To get the width of your PCB trace, you can use the trace width formula. You can use the method to figure out how much current can be transmitted through a given trace.

As seen below, the formula is defined by the IPC 2221 standard.


The letter I now stands for current, and you must treat it as such at all times. T stands for temperature change, and A stands for the cross-sectional area of the trace.

It’s worth mentioning that you may obtain the trace width by rearranging the equation and determining the cross-sectional area required for a given current to flow smoothly.

(Current [Amps]/ (k*(Temp Rise [deg. C]) 0.44)) (1/0.725) Area [mils2] = (Current [Amps]/ (k*(Temp Rise [deg. C])

When establishing a reasonable width, keep in mind the thickness of your trace.

Width [mils] = Area [mils^2]/ (Thickness [oz]*1.378[mils/oz])

Since it only allows temperature increases from 100C to 1000C, the PCB Trace Width Formula can be used for 0-35 amperes. In addition, the formula accounts for a trace width of 400 mils.

Keep in mind that the PCB Trace Width Calculation Formula is the industry standard, and most PCB manufacturers think it is accurate. It may, however, not be appropriate for every design. As a result, it’s important to understand that they won’t be held liable for any damage it causes.

FAQs regarding PCB Trace Width Calculation

Is there a limit to the current quantity in a PCB Trace Width Calculation?

The IPC 2221 standard, from which these methods are derived, allows for up to 35 amps, a maximum trace width of 400 mils, a moderate temperature increase of 10-1000C, and a copper material of 0.5-3 oz/m2.

What does a temperature rise mean in this context?

The difference between the optimum working temperature and your PCB’s standard working temperature is referred to as temperature rise. It’s necessary to keep in mind that increased current transmission raises the temperature of the trace. As a result, the temperature increase is a design factor that influences the heat capacity of your PCB.

What unit of measure is a Mil?

A Mil is a standard measuring term in the technological world, and it is defined as 1/1000 of an inch.


Many factors determine trace characteristics in the PCB world, therefore while routing your next PCB, try to follow best practices to achieve a balance between PCB fab cost, circuit density, and overall efficiency.

Printed circuit boards are the basis of many electronic devices. To avoid your printed circuit board from being destroyed, you must first determine its trace width. You may also determine the amount of current carried by determining the trace width. To make a good PCB, remember to follow all of the standards specified above.