PCB Trace Calculator- Everything You Need To Know in 2024


PCB trace calculator is a crucial part of PCB assembly. This online tool helps calculate the maximum current through the PCB trace, voltage drop, inductance, trace impedance, and power. It provides the best result considering the copper weight used in your PCB trace.

PCB Trace Parameters

PCB Trace Parameters

Do you have a clear concept about a PCB trace calculator? Do you have any idea how it functions?

Don’t worry. We are here to solve your problems. This article will deliver you the ins and outs of the PCB width trace calculator, PCB trace max current, PCB trace inductance calculator, etc.

We hope it will upgrade your PCB experience to a great extent. Let’s start.

What Is A PCB Trace Calculator?

PCB trace calculator is an effective tool that measures the parameters related to PCB trace, like trace width, temperature rise, highest current, etc.

Basically, PCB trace calculators are designed considering their online applications. Nowadays, PCB manufacturing service is very advanced and everyone demands optimum precision in trace design. In that sense, these calculators play a vital role in upgrading the manufacturing process through their automated calculations.

PCB Trace Calculator

PCB Trace Calculator

Trace calculators usually take care of almost every factor related to printed circuit board traces. You can measure voltage drop and power consumption, along with knowledge of the highest current carrying capacity of PCB traces.

That means you can minimize the faults in PCB trace design to a large extent. Doesn’t it sound amazing?

We think these facilities are outstanding from the point of view of PCB productions.

Why Use A Trace Calculator?

It’s a good question. If you are familiar with PCB designing and other segments of manufacturing, trace calculators are very common for you. It is obvious that these calculators can upgrade your PCB experience to the next level.

Importance Of PCB Trace Calculators

Importance Of PCB Trace Calculators

Now, the key reasons for using a trace calculator are-

  • You can find out the suitable trace resistance, power consumption, voltage drop, Amperage, inductance, capacitance, etc.
  • It ensures design stability in multilayer and single-layer PCB assembly services.
  • You get an idea about which metallic coating will be perfect for your PCB trace.
  • It allows you to match impedance between different layers which improves the signal propagation capacity.
  • Perfect calculation of trace components helps handle distortion in high-speed signals.

Does Temperature Rise Affect PCB Trace Calculation?

Off course. Temperature rise is an unavoidable factor for PCB trace calculators. You must consider this issue while setting your parameters. But voltage drop and resistance limit its effect in PCB trace calculation.

Do you know how? Let’s have a look.

Excessive temperature rise, for example, 100 ⁰C is not a problem for regular FR4 PCB traces. But it affects the ambient temperature of adjacent components which is an alarming issue for PCB designers.

Sudden temperature rise causes high power dissipation in PCB traces. It ultimately increases power loss in electronic systems. Besides, temperature rise often mismatches with voltage drop. When you set a reasonable voltage drop level, you can find that the rise of trace temperature becomes low.

PCB Trace Current Vs Temperature Graph

PCB Trace Current Vs Temperature Graph

Moreover, it affects the production cost to a large extent. You need to pay the additional costs to deal with heat dissipation or voltage drop.

That’s why manufacturers prefer 2 oz copper for the PCB trace rather than facing so much hassle. Considering the availability, 2 oz copper is a cost-effective option for the external layer.

Along with these issues, you also need to consider glass transition temperature and CTE (Coefficient of Thermal Expansion). The maximum operating temperature should be around 130°C for FR-4 to maintain electrical properties.

If the highest temperature of your PCB trace will not exceed 60°C, it allows you to go for around 70°C rises. This can be 105°C For FR-2. That means the limit is actually a 35°C rise. How can you ignore the consequences of this temperature rise?

All of these indicate that temperature rise in PCB traces needs to be considered with close attention. Otherwise, you don’t experience the optimum benefit of using a PCB trace calculator.

Current Limit For PCB Trace Width Calculator

It is very common for PCB designers to face problems in determining the maximum current limit for the PCB trace. In many cases, designers who lack expertise in this sector, use the default values without considering the practical cases. But is it reliable to depend on default trace dimensions, especially trace width?

We don’t think so. But how can you define the current limit of the PCB width trace calculator?

Let’s find out.

You need to pay attention to trace impedance, termination, resistance, signal frequency, etc while dealing with PCB trace width max current.

Usually, people ignore trace resistance during the width selection. But it brings out serious hazards. All traces have significant resistance that influences the power dissipation and voltage drop. So, if you don’t care about trace resistance, it causes unusual current conduction. This phenomenon leads to high power consumption that results in the destruction of PCB traces through burning or delamination. That’s why you must find the answers to the following queries first-

  • What is the copper thickness used in PCB traces?
  • What’s the dielectric constant?
  • What is the Coefficient of Thermal Expansion (CTE)?
  • What is the position of traces (outer or inner PCB layers)?
  • What is the length of the PCB trace?

These answers can provide you with a better understanding of the max trace current concerning trace width. Usually, thicker copper layers can handle higher current loads. The thickness of the copper layer and the trace width is inversely connected. So, you need to keep the trace width low to take care of overloads. But the production cost will increase to a certain degree in that case. That’s why you need to make a balance between them.

In most cases, manufacturers prefer 0.5 oz-10 oz copper thickness. Again, you need to use a higher copper weight for a multilayer PCB stackup.

You can measure the maximum current conduction through PCB trace by using the equation mentioned below-

Maximum current

Here, b and c are constants. Their values are 0.725 and 0.44 respectively.

PCB Trace Current Capacity

PCB Trace Current Capacity

PCB Trace Resistance Calculator

Resistance is an important property of electric devices. It refers to the measurement of opposing the flow of current. PCB trace resistance calculator is a must-have part of PCB manufacturing as resistance affects the performance of PCB performance to a great extent.

So, you need to calculate how much resistance a PCB trace can provide. To calculate PCB trace resistance, The 50 ohm PCB trace calculator is designed considering the following formula.


Here, = resistivity at copper

= 1.7 10^(-6) Ohm-cm

T= Experimental temperature

= room temperature (25⁰C)

L= Length of trace

= copper temperature coefficient of resistance

= 3.9 10^(-3) /⁰C

A= cross-sectional area

Required Parameters For PCB Trace Resistance Calculator

Required Parameters For PCB Trace Resistance Calculator

Necessary Parameters For PCB Trace Impedance Calculator

PCB trace impedance calculator measures the approximate impedance of a circuit board. In this case, designers ignore surface finish thickness. As this calculator delivers a rough output, further you need to calculate the final impedance through a different process.

There are various parameters set in the function of the PCB trace impedance calculator. Such as-

Parameters For Symmetric Stripline  

  • Impedance (Zo)
  • Relative permittivity
  • Track width
  • Track height
  • Loss tangent
  • Isolation height

PCB Trace Calculator Parameters For Symmetric Stripline

PCB Trace Calculator Parameters For Symmetric Stripline

Parameters For Surface Microstrips

  • Impedance (Zo)
  • Dielectric constant
  • Track width
  • Track height
  • Dissipation factor
  • Isolation height

Parameters For Edge-Coupled Surface Microstrip

  • Impedance (Zo)
  • Impedance (Zdiff)
  • DK value
  • Track width
  • Track height
  • Isolation height

Required Parameters For Edge-Coupled Surface Microstrip In PCB Trace Calculator

Required Parameters For Edge-Coupled Surface Microstrip In PCB Trace Calculator

Watch this video about KiCAD controlled impedance traces:

The Importance Of PCB Trace Width Calculator

PCB trace calculators are a worthwhile online solution to determine PCB trace width. Trace width is an essential parameter for the designer while handling PCB designs with high layer counts.

So, the trace width calculator’s importance is beyond question. The most significant advantages of PCB trace width calculators include-

  • It helps keep the trace current and temperature within a certain limit to avoid overheating.
  • It ensures the safety and longevity of PCBs used in different sectors, like the medical industry, automobile, aerospace, etc.
  • Trace width calculators provide you the information of the highest considerable current flow through the PCB trace, without causing severe damage.
  • Proper trace width is a must for the trace to be functional for a long period. In that sense, trace width calculators have immense significance.
  • Trace width calculators deliver necessary details about internal and external layering by measuring voltage, inductance, impedance, etc.

We think it is crystal clear to you the necessity of PCB trace width calculators in PCB manufacturing, isn’t it?

How To Calculate The PCB Trace Width Through A Trace Width Calculator

You can calculate the value of trace width suitable for PCB by using a Saturn PCB trace calculator. In the case of 1 oz copper, you have to follow this formula:

Trace width, w= A/T x 1.378 mils


Trace thickness, T=1.37 mils (for 1 Oz copper PCB), A= Cross-sectional area (mils^2)

This area can be determined by the following equation.


Here, I=Required current (amps), K= Layer constant.

According to the IPC-2221,  K= 0.024 (inner layers)

K= 0.048 (outer layers)

You can check this video to get a better idea:

How To Calculate Parasitic Capacitance Of PCB Trace

Usually, a PCB trace capacitance calculator can measure the parasitic capacitance. But do you have any idea why this capacitance is so important for PCB trace?

Let us explain.

Parasitic Capacitance Of PCB Trace

Parasitic Capacitance Of PCB Trace

Parasitic capacitance is an unwanted property of electronic applications that is caused when two electronic components come close to their proximity. Its other name is stray capacitance.

It has an adverse impact on high-density and high-speed signal transmission systems. Parasitic capacitance can alter the intended result of an electronic operation. Besides, it creates an alternative feedback path between the input and output of amplifier circuits. This feedback causes parasitic oscillation in the device which is not desired at all.

That’s why the calculation of parasitic capacitance is highly important. But how?

Usually, PCB trace calculators are designed through the following equation-


It is mainly used to determine parallel plate capacitance. Here the area of the plate is considered very large and the distance between two plates is assumed as negligible. But these values are not always as assumed in practical cases. That’s why you need to use a different equation to calculate trace parasitic capacitance.

The following formula is comparatively a better choice for this case-


Here, h= half of the distance between wires

b= radius of the wires

In this case, all wires are considered circular.

Rule Of Thumb For PCB Trace Inductance Calculator

PCB trace calculators are effective for determining trace inductance in signal transmission processes. In order to calculate the trace inductance, you need to follow some rules of thumb. Do you know about them?

Nothing to worry about. We are here at your convenience. Let’s have a look at the rules of thumb of the inductance PCB trace calculator.

PCB Trace Impedance Calculation

First, you need to determine the trace impedance. Usually, PCB designers use IPC-2141 standard formulas to measure PCB trace impedance. These equations are appropriate for the signal frequency of below 1 GHz used in both stripline and microstrips.

Trace Impedance Calculation

Trace Impedance Calculation

These equations are not completely flawless because there are some arguable assumptions while determining these formulas.

The major deficiencies of these equations include-

Combination Of Skin Effect And Copper Roughness

In these equations, two factors are grouped and they can’t be separated through these rules of thumb. These factors are skin effect and copper roughness. But these do not work similarly in all materials.

That’s why PCB trace inductance calculators can’t deliver the correct results in the case of all PCB fabrication processes. Besides, trace calculators provide different outputs concerning versatile PCB materials as they have separate skin effects and copper roughness.

No Consideration Of Loss Tangent

Loss tangent or dissipation factor is a vital factor in PCB signal transmission systems. It indicates deficiency as you can measure attenuation through loss tangent. According to the IPC-2141 standard, the loss tangent of PCB materials is not taken into account.

Each PCB trace has a dissipation factor that improves the trace impedance by increasing reactance to a certain extent.

Are you starting to think about the necessity of thumb rules in PCB trace calculation?

Don’t make mistakes. These equations undoubtedly have some errors. But you can start calculating PCB trace impedance that leads to trace inductance during PCB design.

Inductance and capacitance combinedly help determine impedance. Besides, you can get an estimation of coupling caused through crosstalk in high-frequency signals. Most noteworthy, you can get a clear understanding of signal behavior in some systems. So, you just need to pay close attention to these rules of thumb.

Is There Any Deviation Of Rules For PCB Trace Inductance Calculator?

PCB traces have particular impedances. The design method goes in the reverse direction only for low-volume and low-frequency signals where you find a requirement of low impedance.

UltraCAD PCB trace calculators measure the signal capacitance according to the IPC-2141 equations.

Signal Capacitance Of PCB Trace

Signal Capacitance Of PCB Trace

You can get two formulas for trace inductance in the case of microstrips and strip lines by using the equations mentioned above.

Inductance Calculation Through PCB Trace Inductance Calculator

Inductance Calculation Through PCB Trace Inductance Calculator

But PCB trace inductance calculators break the rules of thumbs in these cases. As these formulas follow the logarithmic rules, they are designated for some particular values. If you find the logarithmic values less than 1, PCB trace inductance will be negative.

So, how to solve this issue?

To make a convincing solution, those equations are changed a little bit and expressed in the form of ratios. Such as

Modified Equations For Trace Inductance Calculation

Modified Equations For Trace Inductance Calculation

If you take the following value in the PCB trace inductance calculator as

Copper trace thickness= 0.5oz

Dielectric thickness=0.8mm

Number of layer=4

Dielectric constant=4.2

Trace impedance= 50 ohm

Then, the trace inductance will be 6.68 nH/inch.

This value can’t prove the adequacy of IPC-2141. That’s why you don’t need to use the outdated IPC-2141 formulas for determining PCB trace inductance. You can break these thumb rules and apply different approaches for this purpose.

Rules For Minimizing Propagation Delay In High-Speed PCB Design

Propagation delay is a crucial factor in high-speed PCB applications. You need to set the PCB trace dimensions in such a way that the propagation delay becomes minimum. But how?

You need to focus on signal integrity and trace routing. A well-designed propagation delay PCB trace calculator can deliver your desired output in this case compared to the manual trace adjustments and calculations. It can ensure that high-speed signals remain synchronized throughout the PCB trace without causing skew.

You can follow the guidelines mentioned below to compensate for propagation delay to a certain extent-

  • Use high-quality design software like Altium Designer, KiCAD, etc. This software ensures desired signal integrity during high-frequency signal transmission.
  • Incorporate an autorouter in high-speed PCB traces. It interfaces with the design rules and prevents propagation skew.
  • Choose the most suitable trace routing strategy for calculating PCB trace dimensions. It reduces the possibility of resynchronization of high-frequency signals.
  • Choose the right stackup for high-speed trace designs. This can upgrade the functionalities of the PCB trace calculators and reduce propagation delay.

PCB Trace Length Calculator

Are you a regular user of CAD (Computer-Aided Design) tools?

Then, you must have already known about the PCB trace length calculator. It’s a pivotal element of the semiconductor industry, especially in PCB trace design. A proper trace length can ensure signal transmission, almost free from skew and propagation delay.

While designing PCB trace routing, it is necessary to keep the trace length within its threshold value. Usually, the designer determines microstrip and stripline trace lengths separately in order to check the length.

PCB Trace Length Calculator With Altium Designer

PCB Trace Length Calculator With Altium Designer

In the case of routing a circuit board, you must ensure that the trace length matches the PCB layout. As all PCBs are made of versatile materials, like FR4, CEM-3, CEM-1, metal cores, etc. Besides, a complicated design creates some parasitics that increase propagation delay.

That’s why you need to set the parameters in the trace length calculator considering all probable parasitics, relative permittivity, loss tangent, etc.

Most importantly, PCB trace length has an impact on impedance matching. But what’s the secret of maintaining a matched trace length?

Firstly, you can incorporate a built-in trace length calculator that ensures impedance control during PCB routing. It also assures you of matching differential pairs with parallel nets while remaining between the timing tolerances.

Next, you should build a proper layer stack for your circuit board. This can optimize the trace length in the long run.

Last but not the least, apply high-speed design techniques while handling high impedance PCB traces.

Why Do You Need To Know PCB Trace Length?

Knowing PCB trace length is mandatory for many reasons. Among them, the most crucial points are-

  • Be compatible with versatile PCB trace requirements. For example, a PCB antenna requires a certain dimension to be synchronized with the desired signal frequency.
  • While dealing with parallel net data, you must use matched trace length within the tolerances. So, proper calculation of PCB trace length is a must.
  • Trace length and dielectric constant have significant influences on the speed of digital and analog signals through the PCB trace.

We think these reasons are more than enough to use a PCB trace calculator that measures the trace length perfectly.


Do you still have any confusion about the importance of the PCB trace calculator?

We hope this article enables you to understand functionality, significance, etc. PCBMay is a dependable PCB manufacturer in China that utilizes PCB trace calculators while designing a circuit board trace. If you have more things to know about the PCB trace calculations, contact us. Our support team will respond to you within the shortest possible time.

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