Cutting accurate circles in wood can be tricky without the right setup. That is why I built this router circle jig — a reusable and adjustable jig that lets me cut clean circles in different sizes without measuring and tracing each one by hand.
I wanted something more versatile than a simple fixed-pivot circle jig. With this version, I can adjust the pivot point, set the circle size precisely, and reuse the same jig for different projects. It takes a little more work to build, but that extra effort makes it much more useful in the workshop.
Another important part of the design was keeping the base as thin as possible. The router sits directly on the jig, so a thinner base leaves more of the router bit available for cutting while still keeping the jig flat and rigid.
There are several ways to cut a circle in wood, but a router is one of my favorite options when I want a smooth, accurate edge. I also have a Universal Router Circle Jig for a different setup, as well as a Table Saw Circle Jig if you prefer working on the table saw.
In this guide, I’ll show you how I built the jig, how the adjustable pivot works, and how I use it to cut accurate circles in wood.
Router Circle Jig Video
If you want to see the complete build before getting started, watch the video below. I show how I make the base, build the adjustable pivot, assemble the jig, and set it up to cut circles with a router.
Seeing the jig in use also makes it easier to understand how the pivot point and measuring scale work together when setting the circle size.
If you enjoy the video, I’d really appreciate it if you subscribed to my YouTube channel. It helps me keep creating more woodworking jigs, workshop projects, and step-by-step build guides.
Table of Contents
- Router Circle Jig Video
- Router Circle Cutting Jig Plans
- Materials and Tools
- General Questions
- How difficult it is to make a router circle jig?
- What router bit do you use to make a circle?
- How do you cut a perfect circle with a router?
- How to Make a Router Circle Jig
- Making the Circle Router Jig Base Unit
- Cut the Base Desks
- Fix the Desks Together
- Attach the Router to the Base
- Make the Pivoting Pin for the Circle Jig
- Build the Pivoting Pin
- Make a Wooden Knob
- Assemble the Router Circle Jig
- Making the Circle Router Jig Base Unit
- How to Cut a Circle with a Router Circle Jig
- Woodworking Jigs Used
*Safety is your responsibility. Make sure you know what you’re doing and take all necessary safety precautions while working with power tools. Safety comes first!
Router Circle Jig Plans
You can download the Router Circle Jig Plans below if you want the main dimensions and layout organized in one place while building the jig.
The plans are useful alongside the step-by-step guide below, especially when cutting the base pieces, positioning the router, and setting up the adjustable pivot.
Materials and Tools
Before starting the build, prepare the base materials, pivot hardware, and the basic tools needed for cutting and routing. The jig itself is made mainly from MDF and plywood, with a small brass pin and an M6 bolt forming the adjustable pivot.
Wood / Sheet Material:
- MDF base piece – 515 × 103 × 5 mm finished size
Start with a wider piece, around 515 × 200 mm, and trim it later. - Plywood upper/base piece – 445 × 103 mm finished size
- Plywood slider – 100 × 15 mm
Hardware:
- 1 × M6 bolt, 25 mm
- 1 × T-nut
- 1 × wooden knob or wing nut
- 1 × brass rod, Ø4 mm × 10 mm
- 7 × countersunk wood screws, 10 mm
- Self-adhesive measuring tape
Check all the Tools I Use
Tools:
- Circular Saw – https://amzn.to/4aMD0xg
- Jigsaw – https://amzn.to/3S85cDr
- Trim Router – https://amzn.to/3HbQcOg
- Hand Drill – https://amzn.to/3HqLEnH
- Spring Clamps – https://amzn.to/41Nuh9D
- F-Clamps – https://amzn.to/48ArzY1
- Chisel Set – https://amzn.to/3tHNJrT
Machinist Square / Speed Square
Other:
- Router Bit Set – ø6mm, ø12mm – https://amzn.to/3NQNDVX
- Wood Glue – https://amzn.to/48ltKhJ
- Epoxy – https://amzn.to/3tJ5R4L
- Double-Sided Woodworking Tape – https://amzn.to/3tPMGpM
- Sandpaper Sheets – https://amzn.to/41OMx2p
- Self-adhesive measuring tape – https://amzn.to/3TTjGZb
- 7x Countersunk Wood Screws – 10 mm – https://amzn.to/41PodgQ
We may earn an affiliate commission when you buy something through our retail links. As an Amazon Associate, AllFlavor Workshop earns from qualifying purchases.
Before You Start
What Is a Router Circle Jig and Why Use One?
A router circle jig is a simple guide that lets the router rotate around a fixed pivot point, making it possible to cut accurate circles and arcs in wood. The distance between the router bit and the pivot determines the circle size.
This version is adjustable, so you can move the pivot point along the jig and set different circle sizes without rebuilding the setup each time. That makes it much more useful if you plan to cut circles regularly rather than just once.
How Difficult Is This Router Circle Jig to Build?
This is not the simplest circle jig you can make, but the added complexity gives you much more control. The adjustable pivot, measuring scale, and thin laminated base take a little more time to build, but they make the jig easier to reuse and set accurately later.
I would consider it an intermediate woodworking project. You need a router and basic cutting and drilling tools, but none of the individual steps are especially complicated if you work carefully.
Durable motor delivers the power to meet the toughest applications
What Router Bit Works Best for Cutting Circles?
A straight router bit works well for most circle-cutting jobs, especially if you make several shallow passes instead of trying to cut through the material at once.
A spiral up-cut bit is another good option. It generally gives better chip clearance and maintains more consistent cutting contact, which can help produce a cleaner edge. Router Circle Jig
💡TIP: Whatever bit you use, make multiple shallow passes. It reduces stress on the router and bit and usually gives a cleaner cut.
Smooth and precise cut. Exceptional chip ejection to allow cleaner cutting
Let's Begin
The overall dimensions of this circle jig are 515 x 103 mm, which will allow you to cut a circle with a maximum diameter of 640 mm. The smallest possible circle that you can cut will have a diameter of 20 mm.
The circle jig consists of 2 main parts:
- Base unit – the base unit is made out of MDF and plywood – these materials are strong, don’t warp, and keep a flat surface. The thinner the base the better so that a sufficient remaining length of the router bit can be used. Nevertheless, the base unit still needs to be thick enough to withstand some pressure. The router is attached to the base unit.
- Pivoting pin and the adjustable runner. The pivoting pin is made of a brass rod and the runner is made of plywood. They serve for setting up the diameter of the circle and fixing the router jig while making the cut.
NOTE: All router bases have different sizes. Take into account the size of your router base so it fits perfectly for your jig. Adjust the dimensions of your jig so the router fits perfectly.
How to Make a Router Circle Jig
Step 1: Make the Circle Router Jig Base Unit
Start by cutting the MDF and plywood desks for the base. I cut 2 larger pieces around 200 mm in width each that will be cut to size in a later step. These 2 desks will create a t-track for the pivoting pin.
The thickness of the MDF piece is 5 mm, which makes the piece strong enough, but at the same time, it does not take much from the length of the router bit.
TIP: The reason why I am using an MDF as a base piece is that it slides quite nicely on other materials. You could also use HDF as well, or an acrylic sheet but that would be more costly.
1) Cut the Base Desks
Place the router (with the footplate) on the edge of the MDF desk and mark the width of the router base. Make a mark on each side of the desk.
Cut a groove along the desk leaving 45 mm from each of the sides using a ø16mm router bit. The groove will be cut right in the middle of the desk. I used a spirit level as a guide rail to make a straight cut but you can use any other straight edge guide.
Measure the width of the measuring tape and cut a shallow groove right next to the first one. The depth of the slot should be just enough to sink the tape.
This is the bottom of the circle jig which will be facing down.
Follow the same process with the second base piece (plywood piece). Use a ø6mm router bit to cut the groove. Leave 50 mm on one side and 40 on the other.
2) Fix the Desks Together
To cut out the desired shape temporarily fix both pieces of the circle router jig together using double-sided tape.
Draw the design on the base piece and cut off the wood excess. One side of the jig is wider. That’s where the trim router will be attached to it. To make a straight cut I used this Circular Saw Guide Track
Separate the pieces again and cut off the extra wood from the plywood piece so that the router nicely fits in. (The router will be attached to the MDF desk only).
3) Attach the Router to the Base
NOTE: Before moving forward make sure the router is turned off, the cable unplugged, or the battery removed.
Remove the footplate from the router by unscrewing the screws from the footplate.
Trace the holes from the footplate onto the MDF desk.
Drill the holes with a ø6mm router bit and a ø10mm Forstner bit to countersink the holes for the screws to make them flush with the bottom of the base piece. (To attach the router to the base plate I am using the same screws that I unscrewed from the footplate)
Find This Blog Post Useful?
Join my newsletter to receive the latest news, tutorials, and project plans sent directly to your inbox!
Step 2: Make the Pivoting Pin for the Circle Jig
1) Build the Pivoting Pin
The next step is to make the pivoting pin and the slider. The pivot pin is a ø4mm brass pin and is 10 mm long.
First, cut the slider. It is 100 mm long, and 15 mm wide and the thickness is equal to the thickness of the MDF desk. Since the MDF is 5 mm thick and the slider 6,5 I sanded the slider down until both pieces were of the same thickness.
TIP: Round the corners of the slider so it moves easier in the slot.
Drill a ø4,2mm hole for the brass pin on one side of the slider and a ø6mm hole for the bolt on the other side.
NOTE: The distance of the holes from the edge of the slider will determine the minimum diameter of a circle you will be able to cut. In my case, it is 10 mm for the pin and 20 mm for the bolt.
Before gluing the pin and the bolt make sure the bolt’s head is flush with the bottom. You can either carve a hexagon for the head or drill a larger hole with a Forstner bit and use epoxy.
I used the latter since the thickness of the slider is only 5 mm and you need to take into account the head’s thickness. Also, if you have a grinder you can grind down the bolt’s head and make it narrower. That will help a lot.
Once finished with pivoting pin and while waiting until the epoxy hardens you can fix the 2 base pieces of the router circle jig together.
Glue them together and additionally, you can fix them with screws.
2) Make a Wooden Knob
I am using a wooden knob to fix the slider in position but you could also use a wing nut as well.
NOTE: Use a Star Knob Jig to make wooden knobs. If you have a drill press this is a handy jig that allows you to easily and repetitively make shop knobs.
If you don’t have the option then you can make a knob by cutting a circle with a hand drill.
How to make a wooden knob with a hand drill:
- Mark the circumference of a knob. I used a 38mm saw hole for that.
- Drill 10mm holes every 60 degrees. That will create a six-pointed star knob.
- Drill a 6mm hole in the center for the bolt and a 20mm hole with a Forstner bit just enough deep for the T-nut to be flush with the knob.
- Cut out the knobs with a saw hole.
Now assemble all the pieces of the circle-cutting jig together.
Step 3: Assemble the Router Circle Jig
Mount the slider in the groove and secure it with a knob.
Fix the router to the circle jig base with screws.
Mount the router bit and and stick the self-adhesive measuring tape.
NOTE: The position of the measuring tape – before/after the router bit will determine whether you would be working with the outer or inner diameter of the circle. Take that into account when setting the circle diameter.
And the router jig is finished.
How To Cut a Circle in Wood with a Router Circle Jig
The steps below describe how to set up a router circle cutting jig and how to use it to cut a circle in wood. Also, refer to the video included.
How to set up and use a router circle jig
- Prepare your workspace and secure the workpiece firmly to the workbench using double-sided tape. Make sure the workpiece is larger than the intended circle.
- Attach the Router to the Router Circle Cutting Jig with screws.
- Determine the diameter of the circle and mark and cut a center point on the workpiece for the pivoting pin.
- Set the desired radius on the jig’s arm and lock it in place.
- Choose and mount the appropriate router bit based on the type of material cut. For cutting circles, a straight bit or a spiral upcut bit is commonly used.
- Place the Router on the center mark, turn it on, and start cutting. Make shallow cuts and maintain a steady pace.
When cutting smaller circles, I recommend using a 6mm straight router bit.
TIP: Whatever material you are cutting, I recommend making multiple passes. After each pass clean the groove from the sawdust adjust the router bit and continue cutting. Cut off around 3 mm of wood each pass. That will ensure the cuts are clean without any burnings. Every material behaves differently, take that into account.
Repeat the process until you’ve cut completely through.
My Experience
I have been using this router jig for some time now and I am really happy with how it turned out. I have already used it on multiple projects with great success and it is one of the best methods how to cut a precise circle in wood. It is a straightforward build that only requires a bit of time to finish it.
So… If you want to have a nice addition to your for your workshop go for it.
KEEP READING: Best Woodworking Jigs For the Workshop
How to improve the router circle cutting jig
While using this circle jig I came up with an enhancer that would make it even easier to use. Generally, it is quite inconvenient that you have to screw the router base to the jig whenever you want to use it. If you’re cutting circles once in a while I guess it’s okay, but if you’re using it every other day then it gets quite tiring.
- Screw-less attachment. Use a quick-fix attachment to fix the router on the cutting base by placing the router between bearings. This not only solves the problem of attachment but also improves the work with cable routers.
This improved circle jig also uses a pivoting pin which leaves a hole in the circle once you are finished. It would be also good to have the possibility to cut a circle without leaving any marks on the surface.
RELATED ROUTER JIGS:
- Router dado jig – for cutting perfect dados and rabbets
- Adjustable router template guide – to accurately and precisely cut specific shapes in the stock.
- Universal router circle jig – for corded and cordless routers.
