How To Cut a 4×4 With Circular Saw

If you have a 4×4 in one hand and a circular saw in another, you’re 7 steps away from a perfectly cut beam. It’s not as easy as just running the saw across the beam (as you’ll see in a second). In this guide, we’ll explain how to easily cut a 4×4 with a circular saw.

Know the Limitations of Your Saw

If you’re not super familiar with circular saws, you might be scratching your head. Why not just run the saw across the plank and cut it?

When you take a closer look at the tool, you’ll understand. A circular saw doesn’t have the cutting depth to go all the way through a 4×4 beam. You need to know the limitations of your saw before learning how to use it.

Common household circular saws have a blade size of either 6-1/2” or 7-1/4”. These saws have a maximum depth of 2-1/8” and 2-1/2”, respectively. Keep in mind, these figures are just for 90-degree cuts. If you bevel the blade, you’ll have a smaller max depth.

A standard 4×4 beam is a 3-1/2” square. That leaves you with up to an inch leftover after the cut.

7 Steps to Cut a 4×4 With a Circular Saw

Our expert team of woodworkers will now walk you through how to cut a 4×4 with a circular saw. Don’t worry, the process is really easy. We’ll take our time explaining it and break it down into 7 easy steps.

Step 1: Secure It

Before making any cuts, you need to make sure the beam is secured and supported. You never want to cut an unsecured beam – especially when final presentation and accuracy matter.

In most cases, you should clamp the beam to a solid table. If the beam is long and you’ll have a lot of overhang on both sides, you can get away with just resting it instead of clamping it.

While securing the 4×4, make sure it’s level. This process won’t work if the beam is angled in any direction.

Step 2: Measure It

How long do you want the final piece to be? Time to measure your current piece and mark the area that you need to cut.

The best practice is to measure twice, cut once. That means that you want to re-measure and ensure you did everything right before making your cut.

The way to mark the beam is to use a pencil and a square. Mark the one face along the square then rotate the beam and mark the next face. You should measure the length of each face before marking it, and ensure that the line is continuous all the way around the 4×4.

When all four faces are marked, check to make sure they’re all square from the beam (assuming you want a 90-degree cut).

Step 3: Line Up the Blade

Grab your circular saw and make sure the blade is square. Again, this is assuming you want a flat top and a 90-degree cut. If your circular saw can bevel, it’s imperative that you set it at its origin and ensure the angle is correct.

Step 4: Cut It

It isn’t until this step that you’ll actually cut the wood. Being smart about your preparation means that you won’t miscut a beam and waste your time, material, and money.

The saw should be set to the deepest depth and squared. The shoe should also be square to the blade. Make a slow cut from the scrap-end of the beam. For example: if you want a 5’ length of 4×4 and you measured from the left, your blade should be positioned to the right.

We use this method that way you don’t lose an additional 1/8” or so from the thickness of the blade. Be slow and deliberate with your motion and make sure you follow through the plank to complete the cut.

Step 5: Turn It and Cut Again

Before unclamping or moving your beam, take a look at the line. If it’s complete and you’re happy with the cut, remove the clamps.

Flip the beam 90-degrees (turn it over on its end once). Clamp it again to your workstation and make another cut, taking the same precautions explained in step 4.

You’ll start cutting from the notch left from the previous cut. This might not make sense on paper, but you’ll understand once you get this far in your project.

Step 6: Repeat Steps 4 and 5

Repeat steps 4 and 5 two more times. By the end of this step, you will have made four total cuts and the beam should be separated into two pieces – a scrap side and a usable side.

Step 7: Measure, Sand, and Complete

Check out your finished beam. Make sure the measurement is correct and the finished cut is flush. If it’s not perfectly flat on the top, you might be able to get away with some vigorous sanding to smooth it out. At any rate, the beam is now ready to be used in your project.

Alternative: Use a Saw Guide

If you want to speed up the process quite a bit, you can use a pre-fabricated saw guide. If you have some experience with woodworking and designing, you can also try to make one on your own.

We suggest starting with this part (Click for the guide on Amazon) before trying to make it yourself.

The guide will clamp onto your 4×4 at the desired height. All you have to do is follow the given instructions and you’ll be able to quickly do the 7 steps outlined earlier with ease.


We just outlined how to cut a 4×4 using a circular saw. The blade isn’t large enough to cut through the beam in one motion. Luckily, you can follow our 7 simple steps and you’ll wind up with a perfectly cut piece of wood. Check out the rest of our blog for more tool guides and information.

Help us out by spreading the word!!

Leave a Reply

Your email address will not be published. Required fields are marked *