How To Cut 45 Degrees With a Circular Saw [3 Best Ways]

Last Updated On May 1, 2023

Woodworkers can hardly avoid a 45-degree cut. Making cupboards, window or door trims, boxes, etc., all require a 45-degree cut. Although there are specific tools that can make this process a piece of cake for you with a rough cut, they are expensive, and besides, a circular saw is an effective and affordable tool to get the entire cut job done in perfect alignment.

Cutting a 45-degree angle with a circular saw starts by adjusting the saw blade to 45 degrees and securing a straight edge or guide with clamps. Slowly guide the saw along the guide to make the cut. Verify the angle and adjust as needed.

Even though the process is intimidating at first, hopefully, our step-by-step guide on how to cut 45 degrees with a circular saw will make the process clear to know.

But let’s first take a look at what separates a beveled cut from a miter cut.

What Is The Difference Between Bevel & Miter Cut?

Although sometimes the terms are used interchangeably, they are certainly not the same. Mastering both cuts is important when you want to make seamless cuts and joints.

Miter Cut

A miter cut is more of a cross-cut, where you are cutting along the width of a board. To make a miter cut, you will be looking at the top of the wood, angling the saw blade horizontally to work along the width of the board and sometimes the length.

Further, the reason why you should go for miter cuts is that they make a uniform, clean cut with very little grain exposure. Secondly, it is easier to connect miter joints with the use of a screw, nails, or mechanical tightening tools. 

Bevel Cut

An angle cut down a board’s length or depth is referred to as a beveled cut. A bevel cut is made along the face of the wood. In this cutting line, the angle will move down the top of the board to the square sides. Bevel cuts produce a softer effect that holds up well as the years go by.

You can also hide the joints with a beveled cut as the pieces form complementary angles which overlap slightly to appear as a single piece of wood. 

How To Cut 45 Degrees With a Circular Saw Using Bevel, Miter, & Compound Miter Cuts

Now, let’s take a look at how to do 45 degrees cut with a circular saw in 3 different methods we find the most useful. 

Things You Will Need

• Circular saws
• Carpenter’s pencil
• Sandpaper 
• Speed square
• Clamps

How To Make a 45-Degree Bevel Cut

The most important thing to remember is making an accurate bevel cut takes a tightly clamped guide that will help you cut in a straight line with your saw. As long as your blade doesn’t wobble or veer off course, you will be fine.

Step 1: Marking The Cut Line

After measuring the angle at which you need to make the cut, mark the board surface. A speed square is helpful in making a visible, clean line that you can follow.

Step 2: Place & Secure The Speed Square

Align the marked line with the 45° indicator sticking on the shoe. Position the saw on the board surface. Now, two lines should be visible on the shoe, indicating 0° and 45°. You only need the 45° line. 

After adjusting the speed square onto the shoe, you will have to clamp the speed square securely. As this is our guide to making the cut, make sure that the speed square holds its position.

Step 3: Set The Saw

Before starting, the bevel angle and blade depth of the circular saw needs to be adjusted. The bevel angle adjustment is usually at the front of the saw. To take the saw away from the shoe, loosen the lever. Your saw may have detents at 45°. Now tighten the mechanism. 

To make a clean cut, adjusting the saw’s cutting depth to make the blade stick out minimally below the cutting surface is necessary. Loosen the depth adjustment of your saw. Move back the blade guard to adjust the blade depth so that it extends past the wood by a quarter inch.

Step 4: Sawing The Wood

Adjust the saw to make the edge of the square and the shoe butt against each other. Make the cut. Hold yourself steady till the end. Keeping the shoe aligned with the edge of the square is key to making a clean cut. 

Step 5: Clean Up The Edge

Use sandpaper to get rid of all the loose bits, and you are done.

How To Make a 45-Degree Miter Cut 

Here are the steps to making clean 45-degree miter cuts.

Step 1: Marking The Cut Line

The first step is, after measuring the angle at which you need to make the cut, to mark the work surface. A speed square is helpful in making a visible, clean line that you can follow.

Step 2: Place & Secure The Speed Square

After placing the saw on the board surface, this time, line up the 0° indicator on the show with the cut line. You need to place the speed square against the shoe’s edge. Now, clamp the speed square in place. Ensure that it is secured tightly as it will serve as the guide for the cut.

Step 3: Set The Saw

For this cut, you only need to adjust the blade depth of the circular saw. For that, move back the blade guard to adjust the blade depth so that it extends past the wood by a quarter inch.

Step 4: Sawing The Wood

Adjust the saw to make the edge of the square and the shoe butt against each other. Make the cut. Hold yourself steady till the end. Keeping the shoe aligned with the edge of the square is key to making a clean cut. 

Step 5: Clean Up The Edge

Use sandpaper to get rid of all the loose bits and you are done.

How To Make a 45-Degree Compound Miter Cut 

This cut is a combination of the above two cuts that produces a surface that is angled at two edges. Using a circular saw for that cut won’t produce the cleanest cut. Compound miter saws give out cleaner results. However, if you follow the instructions below, you will still get a decent cut.

Step 1: Marking The Cut Line

Use a speed square to measure and mark the miter line at a 45° angle with a carpenter’s pencil. 

Step 2: Place & Secure The Speed Square

Align the marked line with the 45° kerd indicator sticking on the shoe. Position the saw on the board surface. After adjusting the speed square onto the shoe at the 45° mark, you will have to clamp the speed square securely. As this is our guide to making the cut, make sure that the speed square holds its position.

Step 3: Set The Saw

Before starting, the bevel angle and blade depth of the circular saw needs to be adjusted. Loosen the lever and set it to the 45° indicator before tightening the lever again. 

Loosen the depth adjustment of your saw. Move back the blade guard to adjust the blade depth so that it extends past the wood by a quarter inch. 

Step 4: Sawing The Wood

Adjust the saw to make the edge of the square and the shoe butt against each other. Make the cut. Hold yourself steady till the end. Keeping the shoe aligned with the edge of the square is key to making a clean cut. 

Step 5: Clean Up The Edge

Use sandpaper to get rid of all the loose bits and you are done.

Still, doubts? See the video.

Final Words

Woodworking can be an expensive hobby if you go off buying a new tool for every cut you make. Owning a few basic tools like the circular saw and learning how to make different cuts with it is much more cost-effective. 

Even if the cuts aren’t absolutely precise as they would be with a specialized 45-degree angle cutting tool, with some practice, you will get clean cuts even with a circular saw. 

Hopefully, our guide on how to cut 45 degrees with a circular saw has helped you. We recommend you practice all 3 cuts as each can be useful in making different objects. Remember that, You can use both corded and cordless circular saws for this task.