JLCPCB x EasyEDA: PCB Trace Width and Clearance Calculation

One of the most important details in PCB manufacturing is the trace widths and the spacing between the traces. We will see how to pay attention to and calculate these when designing with JLCPCB's EasyEDA design tool.

First of all, you can work more easily if you specify the unit in mil instead of mm. Because road widths and distances between pins are calculated in mil, so you have to deal with fractions in mm.

Click any blank area on the PCB design page in EasyEDA. Then at the top of the right menu you can see the option where you can change the unit.



Trace Width

Trace width is calculated based on current. Especially if you will have high current paths, you must carefully calculate the trace width. So how is this calculation done?

 There are three important parameters when calculating the road width. 

  • Trace Thickness
    When placing your order from JLCPCB, you can specify the trace thickness as 1 oz or 2 oz.

    If possible try to design your circuit in 1 oz. I will give you a few tips for this. If it is not possible, you can reduce your trace width by half by choosing 2 oz. You should use this option if you cannot fit the trace in your circuit and you do not want to inflate with solder.
  • Trace Width
    You can increase the trace width as much as you want. In this way, you can increase the amount of current you can pass. But if your circuit is already congested, there is no space to pass other traces. This complicates your circuit design. Therefore, you should find the optimum value when determining the trace width.
  • Trace Temperature
    Your trace may start to overheat under high current. This is a normal thing. What matters is how many degrees you allow your trace to increase in temperature. For example, if the temperature of your trace increases by 10 degrees to 35 degrees at an ambient temperature of 25 degrees, this is a perfectly acceptable value.

We can calculate our trace width using these parameters. Of course, you must know the maximum amount of current that will pass through the trace. If you know these, you can determine your trace width in accordance with IPC-2221 standards.


Now everything is automated and you don't have to make calculations one by one. There is a site where you can calculate the trace thickness in accordance with the IPC-2221 standard: Printed Circuit Board Trace Width Tool | Advanced Circuits (

 You can quickly find the trace thickness you need to create by filling in the parameters here according to your own circuit.


I Told You I Was Gonna Give You A Few Tips 

When you increase the 1 oz road thickness to 2 oz, your road width will be halved. You can use the following method for this.

  • Select a trace you drew in EasyEDA.
  • Copy the trace.
  • Paste it.
  • Change the layer of the trace from the menu on the right (if it is in the bottom layer, select the top layer. If it is in the top layer, select the bottom layer).
  • Place your new trace directly above the trace you copied.

Thus, the same trace will be on both top and bottom layers. In this way, your trace thickness will be like 2 oz.


If you are drawing a double layer circuit and using both layers actively, the above method may complicate your circuit drawing. In this case, I can suggest another method.

  • Again, select a trace that you have drawn.
  • Copy the trace.
  • Paste it.
  • Convert the trace layer to the solder mask layer from the menu on the right.
  • Place your new trace directly above the trace you copied.

So your track will be produced uncoated. By inflating your uncoated trace with solder, you can allow high currents to pass.


Trace Clearance 

The gap between the traces is calculated according to the voltage. But contrary to popular belief, current is also important most of the time. I will address the reason for this.

In high voltage lines, if the opposite lines are too close to each other, insulator rupture occurs and current begins to flow through the insulating circuit board. A short circuit occurs and can easily start a fire. This is a very dangerous situation. So how much space should be left at how many volts? It also has certain standards. IPC-2221 standards are accepted standards. We can calculate according to these standards. Again, there is a site where you can calculate spacing in accordance with the IPC-2221 standard: PCB Trace Spacing Calculation for Voltage Levels (


The point you should pay attention to here is that if you are calculating the gap for AC, you should enter the peak voltage, not the RMS voltage in AC. For example, to find the maximum peak voltage of the 220V mains voltage, you must multiply by 2 (220V * 2 ≈ 312V).

If you are going to inflate the trace with solder, that is, if your trace is uncoated, you should base the "external" value. If your path will not be bare, that is, it will be coated, you should base the "coated" value. If your trace is coated, it will naturally be safer, so you can leave less space between traces.

If possible, you can cut between these traces with Board Outline. This will increase your creepage distance. This provides increased safety.



Also, if you look carefully at the pictures, here the high voltage and signal line are insulated from each other, not the two high voltage lines. I mentioned that the gap distance is also important for the current most of the time. I want to explain this.


It creates a high magnetic field around a high current line. This causes serious interference in the surrounding signal lines. Especially if interference occurs on the GND line of your circuit, it will affect the operation of everything. Therefore, if you have a high current line, I recommend that you leave as much space as you can between the signal line and the high current line. The magnetic field has nothing to do with the creepage space. The important thing is that the current flowing line moves away from the signal line. Because the magnetic field is proportional to the square of the distance.


JLCPCB Capabilities 

When you calculate the width of low current traces, you may encounter very low trace widths, but in this case, you should not ignore the production capabilities of JLCPCB.


 As seen in the picture, if you are designing 1-2 Layers PCB, you can use a minimum of 5 mil trace thickness and 5 mil trace space. This one is also quite thin and carries about 268 mA of current. For signal lines, it is often quite a sufficient value.


While designing in EasyEDA, make sure that the track width and clearance rules are set to 5 mil to avoid Design Rule errors. You can access these settings from the top menu. (Make sure the unit is in mil)


Thus, while making your design in EasyEDA, if you make the gap between traces or trace width shorter than 5 miles, EasyEDA will warn you.

Now you can make your PCB designs in a much safer, standards-compliant way.

You can also follow Project 777 - Berkay EVREN - YouTube channel, which is the main sponsor of JLCPCB, for such tips and detailed design videos with EasyEDA. 

JLCPCB Part-Time Engineer / Berkay EVREN