Routing a Circle: How to Cut Perfect Circles on a Router Table
A router is one of the best tools for creating smooth, accurate circles in wood. You may already be familiar with using a handheld router and a trammel to cut round tabletops or circular panels. But there's another approach that's just as useful — cutting circles on a router table.
Instead of moving the router around the workpiece, the router bit stays stationary while the workpiece rotates around a pivot point.
The secret is a simple, shop-made circle-cutting jig that uses a swing arm and adjustable stop to control the final diameter.
Build a Simple Router Table Circle-Cutting Jig
The jig consists of three basic parts: an auxiliary tabletop, a swing arm, and an adjustable stop.
All three components can be made from 1/4"-thick hardboard, making this an inexpensive jig that's easy to build.
The auxiliary tabletop sits over your router table and extends beyond the front and sides to provide room for the swing arm.
The arm attaches near the front left corner of the auxiliary top using a bolt, washers, and a nut. This allows the arm to pivot smoothly toward and away from the router bit.
A series of holes drilled along the swing arm accepts a pivot pin. By selecting different holes, you can position the workpiece for different circle sizes.
The adjustable stop limits how far the swing arm can travel toward the bit, determining the finished diameter of the circle.
Set Up the Router Table for Cutting Circles
Start by installing a straight bit in your router table. I prefer a spiral up-cut bit because it produces a clean cut and helps clear chips from the cutting area.
Position the auxiliary tabletop over the router bit and clamp it securely to the router table.
Next, rough-cut the workpiece into a circular shape, leaving a little extra material around the outside edge.
Drill a small hole at the center of the workpiece to accept the pivot pin, which can be made from a nail.
Place the workpiece on the swing arm with the pivot pin inserted through the center hole.
Finally, position the adjustable stop to limit the arm's travel and establish the desired finished diameter.
Before routing, make sure the workpiece rotates freely, the pivot pin is secure, and the swing arm and stop cannot shift during the cut. Keep your hands clear of the bit and use suitable work-holding or guarding for the setup.
How to Cut a Perfect Circle on the Router Table
With the jig set up, you're ready to start shaping the circle.
Turn on the router and carefully pivot the swing arm toward the bit until it contacts the stop.
Once the bit engages the edge of the workpiece, slowly rotate the workpiece counterclockwise, as shown in the original setup.
Continue rotating the workpiece through at least one complete revolution to trim the entire circumference.
When the cut is complete, retract the swing arm to move the workpiece away from the bit before shutting off the router.
Make Multiple Passes for a Smoother Edge
For the best results, don't try to remove all the excess material in one pass.
Instead, start with the adjustable stop positioned to make a light cut around the outside of the workpiece.
After completing a full rotation, move the stop back slightly to allow the swing arm to travel a little farther toward the bit.
Make another pass, removing a small amount of material.
Continue adjusting the stop and routing the edge until you reach the desired diameter.
Taking several light passes reduces the amount of material removed at once and helps produce a smoother, more consistent edge.
An Easy Way to Make Round Woodworking Parts
This simple router table jig is a handy alternative to a traditional router trammel.
With just a hardboard top, pivoting arm, and adjustable stop, you can create accurately sized circles for tabletops, shelves, decorative panels, and other round woodworking projects.
And because the pivot arm has multiple pin locations, the jig can accommodate different circle sizes without requiring a new setup for every project.
It's a straightforward way to get more versatility from your router table while producing smooth, accurately shaped circular parts.
More Woodworking Tips & Techniques
Looking for more ways to get better results in your workshop? From clever router techniques and handy shop-made jigs to time-saving tricks for cutting, shaping, and assembling wood, there's always something new to learn.
Explore our Woodworking Tips & Techniques collection for practical, shop-tested ideas that help you work smarter, improve accuracy, and get more from your tools.
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