How to use a circular saw to cut straight

  • Post category:HOW TO'S

One of the most essential skills that you should have when you use a circular saw is creating straight cuts, because that skill will let you apply many maintenances, create beautiful shapes and pieces or create straight cuts for your plywood sheets and longboards.

circular saw straight cut

In this guide, you will learn to easily cut in straight lines using your simple circular saw like a pro. You can do this using a table saw, but not many of us have table saws in their workshop. Creating straight lines and cutting straight pieces of long boards can be done easily and more effectively using a table saw, but with some training, and a little bit of fineness, you will be able to beat the table saw and create smooth yet beautiful straight cuts.

Creating straight edges and cuts using a circular saw can be done easily for small wood boards but when you have large spans of boards, it will be difficult to maintain the straightness.

Before we dive in, you should have some tools that will help us complete that task and you should follow the basic safety rules.

Safety Measurements and tools:

  • Before you start anything, you must wear your safety glasses and gloves
  • Do not use the circular saw with one hand; you must use it with both of your hands, one on the handle at the back, the other on the front handle.
  • Do not touch the upper guard or the lower guard during the operation.
  • Choose the appropriate blades for the type of work to be done.
  • Make sure that the blade does not deviate from its path and rotates freely between the upper and lower guards.

Tools that you will need

  • Circular saw
  • A pencil
  • Tape measure
  • A speed square (Or a steel ruler if you don’t have the speed square)
  • A series of clamps depending on the length of your piece of wood
  • Solid and stable surface (a sawhorse or a workbench)
  • A piece of scrap wood with a straight edge longer than the piece of wood you are going to cut.

It is better to use a piece of plywood because it is perfectly flat and it has quite fixed dimensions. Solid wood is deformed a little (use dry wood instead).

How to make a straight cut using a circular saw

Let’s say you want to cut two inches off a long piece of wood.

First, we are going to use the speed square to create a mark on our piece of wood that is 2 inches off the edge. Actually, you will have to create two marks, one at the beginning of the piece of wood, and the other one is at the end.

The speed square has a lip at one of its sides. You should lay the lip right against the edge of your wood.

speed square steel
circular saw shoe distance

After that, we will have to make some adjustments on our circular saw. The backside of the saw is called the shoe, it is actually the base of the saw. Learn more about circular saw components

Pull back the guard of the blade, take your tape measure, and place it right outside of the blade and measure the distance between the vertical surface of the blade and the end of the shoe. Let’s say it is 1 and ¼ inches.

Create another mark after the mark that we created on the wood, the distance between the two marks is equal to the distance that we have just measured on the circular saw, which is 1 and ¼ inches.

Take the piece of scrap wood and place it right on the new marks that we made on the piece that we want to cut. The new marks should be 3 and ¼ inches away from the edge of the piece we want to cut.

Then we will have to take two clamps and tighten the two pieces of wood together on the stable surface that we have. You need to secure the clamps at both ends.

Take your circular saw, place it on your piece of wood and make sure the shoe of the saw is guided by the scrap piece because the saw is going to slide the guide that we just made. Then start your saw and guide it along the wood path as you cut.

guiding circular saw

How to create a circular saw guide

Cutting plywood with your circular saw is simple and it can actually be safer than using a table saw, but to get accurate cuts, you will need to buy a cutting guide for your saw.

 There are several guides and track saw systems in the market available for purchase, but it is very simple to create your own guide that will work with just any circular saw. This is going to save you a lot of money and time. The only things that you will need is a glue and a sheet stock.

You will need two strips of thin sheet stock to make the following:

  • A wide board for the base of the guide
  • A narrow board for the fence.

You can use tempered hardboard or plywood.

circular saw guide

You will need to make the width of fence strip the same as the greater distance between the blade and the edge of the saw shoe (the base of the saw).

Mark the outside factory edge because that edge is straight and this is important when it is time to assemble the guide.

Now, clamp the sheet stock to the workbench so you can cut the fence strip. Then use the circular saw to cut the fence strip, which its width is equal to the distance that we talked about.

You can put your finger on the outside edge of the saw shoe and let the saw ride along the edge of the sheet stock.

circular saw guide

All you need to do now is to glue the fence stripe to the rest of the sheet and make sure you place the factory side that we’ve marked on the inside of the guide. That way, you will have a nice straight edge. Clamp the two strips and let the glue to dry.

Take the guide out of the clamps and clamp it again to the sawhorses or the workbench that you use because all that’s left to do before the guide is ready is to remove the excess from the guide.

To do that, make a rip cut through the guide but be careful that you should keep the saw base pressed tightly against the new fence as you make the cut.

Now the guide is ready to use.

When you need to cut any sheet or any piece of wood, it is better to place it on a stable surface like a piece of plywood and a piece of foam insulation. This will give you a full support and stability and will let you cut throught the piece of wood and the foam smoothly.

You don’t have to do that, you can use your ordinary workbench or your sawhorse.

To make a cut with your new guide, you’ll first need to mark where you want to cut and place the inside edge of the guide right on the cut marks and you’ll get a perfect cut.


I hope you can see the bigger picture right now about creating straight cuts, you have the choice whether to create your own guide or to buy one, it depends on you. As for me, I used to create my own guide until I bought a new one and I’m still using it. I It costs between 30 to 80 dollars and it really does the job efficiently. I hope you enjoyed the post and I’m looking forward for your comments below.