When you’re cutting down large pieces of plywood with a circular saw, you want them to be straight and accurate. But without a guide, cutting a long straight line with a circular saw can be a challenge.
Sometimes it can even be a challenge to keep things straight when cutting something smaller pieces like a 2×6. It’s just so easy to slightly veer off the path of your pencil line.
In this post we’re sharing 5 ways to get straight cuts with a circular saw. 3 of which will include store-bought guides, and the last two will involve items that you likely already have laying around your workshop.
What You’ll Need:
- Circular saw
- Measuring tape
- Pencil
- Cutting guide (any of options listed below)
Types of Cuts You Can Make With a Circular Saw
Before we dive into the techniques of cutting straight lines with circular saws, I want to quickly talk about the different types of cuts you can make with a circular saw. We will include which types of cuts you can and cannot make with each of the saw guides.
Cross Cut
A cross-cut is when you cut straight across the grain. For most pieces of plywood, this would be when you’re cutting across the 4’ side.
When making cross cuts on plywood, you’re more likely to experience some tearout along the cut.
Rip Cut
A rip cut is when you cut straight with the grain. For most pieces of plywood, this is when you’re cutting along the 8’ side.
Miter Cut
A miter cut is when you cut across the board at an angle. Essentially this would be drawing an angled line across the surface of your plywood and then cutting through the board when the saw blade is still set to 90-degrees.
Bevel Cut
A bevel cut is when you cut through the board at an angle. For this cut, you’re cutting a straight line, but your saw blade itself is tilted at an angle. We used this technique for the top and sides of our DIY entry table.
Marking Your Cuts
Regardless of which method you use (aside from the Kreg Rip-Cut option), you’ll want to start out by planning for your cut in the same way.
Measure and mark where you want to cut on both sides of the plywood. Be sure to pay attention here and double-check those measurements. If you accidentally mark 1/16” off on one side, your line might be straight, but the cut will no longer be square.
If you want to go the extra mile, you can use a drywall square to ensure your lines are square and to connect the two marks you made on either end of the plywood.
For most of the cutting guides listed, a small mark on either side of the plywood will suffice.
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Cutting Guides To Help Cut Straight Lines With Circular Saw
Kreg Rip Cut
Despite its name, you can use this cutting guide for both rip cuts and cross cuts. What makes this guide unique is that you don’t have to mark your measurements on your plywood. Instead, you adjust the built-in measuring scale and lock your measurement in place.
The Rip Cut guide uses the Kreg universal sled which is also used for their Accu-Cut guide. It can easily be attached to most circular saws by tightening two screws.
I will say, the initial set up process for the Rip Cut guide can be a bit confusing, but once you have it set for the first time, it’s very easy to use and adjust.
Once you have it set up initially, you’ll attach the sled to your circular saw and then slide in the measuring scale. Slide until the red line is lined up with the measurement you want, and lock it into place. Slide the handle of the Rip Cut against the wood you are cutting, making sure that the guide is flush with the edge of the wood at all times.
Please note: after you lock the measurement in place, the measuring scale may still rock back and forth. That’s okay as long as it’s not moving side to side and adjusting the measurement. Your guide is not defective. The extra movement will go away when you place the guide onto the plywood and it should not impact your cut.
When to Use:
- Repeat cuts that require the same measurements
- Can use for cross cuts and rip cuts
Pros:
- Least expensive options of the cutting guides mentioned in this article
- No limitation on how long of a piece of wood you can cut
- No measuring tape required
- Make repeat cuts quickly and efficiently
Limitations:
- Cannot cut anything wider than 24”
- May experience more tearout when used for cross cuts
- Requires a straight edge to begin with. Will only cut as straight as the starting edge.
- Cannot be used for miter or bevel cuts
Kreg Accu-Cut
I go back and forth on whether the Rip Cut or Accu-Cut is my favorite cutting guide. The Accu-Cut is extremely versatile and includes a non-slip backing, meaning you place the track where you want to cut and it will stay in place.
Please note: someone has told me that their Accu-Cut does move slightly on occasion. In that case, there are clamps available for the track. We personally haven’t experienced this despite it being a concern when we initially bought the guide.
The Accu-Cut can be used for all sorts of cuts: cross cuts, rip cuts, and miter cuts. It cannot be used for bevel cuts as the angle of the blade might cut the guide itself.
The Accu-Cut is also a track system. You slide your saw onto the track and it guides your saw. I love this, especially for beginners because it takes any pressure away from needing to keep the saw flush with the guide. Once you’re clipped on, you simply push the saw forward, knowing the track is keeping things super straight.
That said, don’t intentionally try to push the circular saw off the track, because there have been reports of people cutting the blue strips of their guide when the saw slipped from the track.
The last thing I want to note about the Accu-Cut is that it has anti-chip strips which help reduce tearout when making cuts. This is especially helpful when making cross-cuts and it’s the only guide mentioned in this post that offers a built-in solution to minimize tearout.
Like the Rip Cut, the initial setup of the Accu-Cut guide can be a bit confusing, but once it’s set up, it’s super quick and easy to use in the future.
Line the side of your Accu-Cut up with the marks you made on your plywood. Lock your circular saw into the universal track and then slide it onto the guide. Once locked into the guide, you can make your cut.
When to Use:
- Cross cuts, miter cuts, and rip cuts
Pros:
- Minimizes tearout with built-in anti chip strips
- No clamps needed
- Track system keeps your cuts straight with less chance of human error
Limitations:
- Need to invest in the XL version to cut longer than 50” long. The XL version allows cuts up to 100” long.
- Cannot be used for bevel cuts
Kreg Straight Edge Guide
This is one of Kreg’s newest cutting guides, so it’s the one we have the least experience with. Here are my thoughts after using it to cut down about 10 pieces of plywood:
The initial setup of the guide is probably the easiest of the three store-bought options we’ve presented. You can also use the guide for things other than just a circular saw, making it very versatile.
It’s also the most sturdy piece of metal so you can feel extra confident that you really are getting a straight edge.
Since a circular saw has a plate, you won’t be lining the actual metal guide with the lines you marked on your plywood. Instead you need to account for how far over your saw blade is from the actual edge of the metal plate that will be against the guide.
The Straight Edge Guide has little black pieces that you will use to set this distance. Once you set it initially, you don’t need to keep measuring the distance to your saw blade. You’ll just line the black tabs up with your marks.
Once you have them marked and the guide clamped in place using its built-in clamping system, push the black tab in so that they are out of the way of your circular saw blade.
Line the metal plate of your circular saw up with the guide and cut, making sure to keep the circular saw plate flush with the guide.
When to Use:
- Rip cuts and cross cuts
- CAN be used for long bevel cuts
Pros:
- Metal guide is study and straight
- Can be used for jigsaws and some routers. Aren’t limited to using with just a circular saw
Limitations:
- Cannot be used for mitered cuts
- May experience more tearout when used for cross cuts
- Need the XL version to cut an 8’ piece of plywood lengthwise. Regular version cuts pieces up to 48” wide.
- If cutting on rigid foam insulation board, the side with the clamp must be off the foam board, otherwise it will raise the guide up off the surface of the plywood. No big deal to set it up this way–it’s just something to keep in mind.
We have only used this guide when working together in the garage. Neither of us has used it by ourselves, so I can’t confirm this, but I have a hunch it would be the most difficult of the guides to use alone.
We have a system where we each line it up on our respective sides and then I push the guide while Andrew tightens the built-in clamp. It’s very quick and effective.
But, if you were working alone, I could see how you can easily slip the further side out of place when trying to tighten the clamp. We even slipped one side out of place when trying to clamp it when we were working together.
Like I said, I haven’t had the chance to try this out on my own yet, so I can’t confirm that it would actually be difficult on your own.
Scrap Wood
This is the option we used when we were first starting out. It’s effective and it only requires a piece of scrap wood, so the cost is minimal. You can continue doing this forever if you prefer. The purchased guides make things quicker and potentially a hair more accurate, but this is a great option if you don’t want to buy something else.
To set it up, find a straight piece of wood. This might potentially be the most difficult step because your cut will only be as straight as your scrap wood is.
Once you’ve found a straight piece of wood, line the circular saw blade up with the line that you want to cut and then mark the side of the circular saw metal plate. Repeat on the other end of the plywood if cutting a long piece. You’ll line your guide up with this line.
Clamp your scrap wood in place to serve as a guide. Make sure your clamps are out of the way so they don’t get caught on your circular saw when trying to make your cut. This is most often a problem when cutting a steep 45-degree bevel cut.
Once clamped in place, line the circular saw plate up with the scrap piece of wood and make your cut, keeping the metal plate of the circular saw flush with the scrap wood.
When to Use:
- Cross cuts, rip cuts, miter cuts, and bevel cuts – works for all sorts of circular saw cuts!
Pros:
- Minimal cost – no premade guide is required
- Versatile – your limit is just how straight and long your scrap piece of wood is
Limitations:
- Requires clamps
- May take additional time to set up
- Have to measure and account for the distance between blade and edge of circular saw plate for every single cut
Speed Square
If you’re cutting down smaller pieces of wood, you can use a speed square as a guide instead. Either hold it in place as you cut or clamp it in place. Guide the metal plate of your circular saw against the speed square as you make your cut.
As with the Kreg Straight Edge Guide and the scrap wood guide, you won’t line your speed square up with the lines that you marked. You’ll line the blade of your circular saw up with the lines you marked and then position the speed square next to the metal plates of the circular saw.
When to Use:
- Cuts on smaller boards like 4x4s and 2x6s
- 45-degree miter cuts on smaller wood like 2x4s
Pros:
- No additional cutting guide needed
- Quick to set up
Limitations:
- Potential to accidentally move the speed square when cutting
- Only works for short cuts
We haven’t personally done it, but we’ve heard of several people who use a drywall square in this same way for longer plywood cuts.
5 Ways to Get Straight Cuts with Circular Saw Summary
There you have it! 5 different ways to get straight cuts with your circular saw:
- Kreg Rip Cut
- Kreg Accu-Cut
- Kreg Straight Edge Guide
- Scrap Wood
- Speed Square
The scrap wood method is the most versatile because you can use it for any size board and any cut. The downsides are that you must find a straight scrap piece of wood to use. Your cut will only be as straight as the board itself. It also requires clamps and is the most time consuming option to set up, which can add up when needing to make a lot of cuts.
My personal recommendation is to invest in the Kreg Accu-Cut and Rip-Cut guides.
We love using the rip cut any time we need to cut more than 1 piece that is the same size. With the Rip-Cut, you just set it (max width is 24”) and make as many cuts as you need. No need to measure between cuts, so you can really get into a cutting groove when you need several pieces of the same.
The downside of these cutting guides is that you cannot make a long beveled cut with either of them. If that’s something you’ll be doing often, I’d recommend the Straight Edge Guide instead.
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If you’re new to woodworking, check out this woodworking for beginners post. We share how to get started and 7 things we wish we would’ve known when starting out! No need to make the same mistakes we did.
