I’ve wanted to build this dado jig for router for some time and regret not building it sooner. I recommend everyone to make it as soon as you get your router.
A router dado jig is a multi-purpose workshop jig that can cut dadoes, grooves, or rabbets. It is suitable for making dado joints, or rabbet joints and can be used as a mortising jig. It is easily adjustable, cheap to build, and really great to use.

The overall dimensions are 700 x 200 mm, which gives you roughly 500 mm to cut dadoes depending on the size of your router base. I’ve built the dado jig for a DeWalt plunge router but it can be built for any router.
This is a beginner-friendly project requiring basic tools. Check out the jigs I used to build it. (see at the end of this article).
Table of Contents
- Router Dado Jig Plans PDF
- Material you will need
- General Questions
- How difficult it is to build?
- What is the difference between a dado and a groove?
- What is the difference between a dado and a rabbet?
- Which router dado bit should I use?
- Step1: Make the Router Jig Base Unit
- Attach the First Guide Rail
- Attach the Second Guide Rail
- Step 2: Assemble the Router Dado Jig
- Fix Both Base Pieces Together
- Make Wooden Knobs
- How to Cut a Dado with a Router
- Router Dado Jig Video
- Jigs used for the project
*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!
Always be cautious and careful when using any power tool.
What you'll need to make the Router Dado Jig
Router Jig:
2x MDF desk (700 x 95 x 5 mm)
-> start with one MDF desk (700 x 200 x 5 mm)
4x Spruce wood (93 x 28 x 5 mm)
2x Spruce wood (220 x 28 x 5 mm)
2x Aluminum L Angles (640 x 14 x 11,5 mm)
10x Wood Screws – 15 x 9,5 mm
10x Washers – for screws above
Dado Router bit – ø6mm Straight Router Bit
Other:
2x M6 Bolts – 35 mm
Double-sided “carpet” tape
Wood Glue
Forstner bit – 10mm, 15mm
M6 T-nuts
Hole saw – 3,8mm
Sand Paper / Sanding Wheel
Tools:
Hand Drill
Trim Router
Clamps
Speed Square
How difficult it is to make a router dado jig?
This is a simple project for woodworking beginners and one of the must-have woodworking jigs for a router. It is not difficult to build the jig, the project is straightforward and you can build the complete dado jig in a day.
See the material list necessary for the project. You will also need a router, potentially a jigsaw, or any other power tool to make the cuts.
What is the difference between a dado and a groove?
The difference between a dado and a groove is in the orientation of how the cut is made. A dado is cut across the grain while a groove is cut with the grain. There is no other difference. Both cuts are often referred to as Slots.
What is the difference between a dado and a rabbet?
The difference between a dado and a rabbet is that a rabbet misses one of the sides. A dado runs across the grain and serves for a dado joint, a rabbet for a rabbet joint. By comparing both types of joints we find that a dado joint is stronger than a rabbet joint since it has a support on each side.

What dado router bit to cut dadoes and grooves?
When cutting dadoes and grooves, you can choose between two types of router bits:
- Straight bit – a double flute straight router bit is a versatile choice that works well for most materials, providing great results.
- Spiral Bit – For cleaner cuts, you can opt for a spiral (upcut/downcut) bit. This type of bit maintains continuous contact while routing, resulting in smoother cuts. An upcut spiral bit also helps in clearing chips effectively. However, keep in mind that spiral bits can be pricier compared to straight bits.
Let's Start!
The router dado jig consists of 2 main parts:
- Base unit – made out of MDF. The thinner the better so that a sufficient remaining length of the router bit can be used (HDF is also a great option). MDF and HDF are great options. The boards are strong, and straight and the router slides smoothly across.
- Guide rails – made out of aluminum. Serve as a guiding fence for the router.
Dado jig dimensions: 700 x 200 x 30mm. Can make cuts up to 500mm in length.
All router bases have different sizes. Take into account the size of your router base, and build the dado jig accordingly. This dado jig is designed for a Dewalt trim router.
NOTE: The router dado jig is designed for one specific router bit size. You decide what size you want to use it with. I am using a 6mm router bit.
How to Make a Dado Jig for Router
Step 1: Make the Router Dado Jig Base
Start off by cutting the MDF desk for the base (700 x 200 mm). The size takes into account the width of the router base, 2 guide rails, extra material for clamping, and a bit of extra material for cuttings. The base will be cut into two pieces in a later step.
NOTE: I decided to go with MDF as the base piece because it is straight and the router slides nicely on it. The thickness is 5 mm, which is sufficient to drill the guiding rails to it, and at the same time, it does not take much from the length of the router bit. An HDF or a 6mm plywood desk would do great as well.

1. Attach the First Guide Rail
Cut two aluminum L angles. They are shorter than the length of the base unit. Take into account space for side wood strips. They are used as stoppers and attach both base pieces together.


Drill 4mm holes in the guide rail every 100 mm. Use double-sided tape to first attach the guide rail to the base and then fix it with screws and washers.
Leave some space from the edge of the board that will be used for clamping (around 25 mm).



IMPORTANT: When using this router jig you always need to use the same size router bit. That is how the jig is designed. That does not mean that you would be limited to making dadoes of that specific width only. If you wanted to use a different router bit you would need to build a separate router jig specifically for that one.
I am using a ø6mm bit. I am often making smaller cuts and a 6mm router bit does well.
Place the router on the base unit against the guide rail and cut across. That will set the exact distance between the guide rail and the router bit, making it zero clearance.

NOTE: There is a good chance the router bit is not centered. So once you make the cut, mark the base piece with the corresponding side of the router so you know which side of the router matches which part of the jig.
Check the setup every time before using the jig. I am matching the front side of my router with the letter A.

2. Attach the Second Guide Rail
Repeat the same process for the second base piece.
- Attach the aluminum L angle, leaving space for clamping.
- Cut the wood excess using the other side of the router. Mark the base piece with the letter B.


At this moment you have 2 base pieces of the router dado jig.

This is the width of one of the jig base pieces which is relevant to my router.

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Step 2: Assemble the Router Dado Jig
1. Fix Both Base Pieces Together
Cut 4 wood strips for each side of the baseboards. The strips will hold the base pieces together using wooden knobs, also allowing to set the desired width of the groove.
Glue the first 2 ones (as they are) to the base piece that will be closer to you when using the jig.


Drill a 10mm hole and a 6mm hole in the center of the other two pieces for an M6 bolt.

Use a chisel to cut a hexagon for the bolt’s head. It is desirable that the head be flush with the wood piece.


Glue the wood pieces on the second baseboard with the bolts sticking up.

To hold the two router base pieces together and to set the width of the dado/groove use a longer wood piece with a routed slot at one end.
NOTE: This way you will be able to set the dado width accordingly and lock the position of both base pieces. In my case, the slot is 6 cm long and 8mm wide which allows me to make dado cuts up to 6 cm in width.
There are a few ways how to cut the slot. I am using this half-built Dado jig – it already serves great as a straight-edge guide.
Anyway, you can use a router table, a drill press, or a coping saw. All of these tools will work well.
TIP: Tape the wood piece down using double-sided tape and clamp the dado jig with the workpiece to a workbench. All will be tight and fixed in place for the cut and the workpiece will not wander around.



2. Make Wooden Knobs
Now the wooden knobs to secure the base pieces in position. If you have a drill press you can use a Star Knob Jig that allows you to easily and repetitively make wooden knobs. I didn’t use the knob jig this time though and I made the wooden knobs using just a hand drill.
How to make wooden knobs without a knob jig:
- Mark the circumference of the knob using a 38mm saw hole.
- Drill 10mm holes every 60 degrees. That will make a six-pointed star knob.
- Drill a 6mm and a 20mm hole in the center of the knob for a t-nut. Make sure the t-nut is flush with the surface
- Cut out the knob with a saw hole.


To smooth the edges I mounted the knobs on a drill press and sanded them using a sanding wheel.

Finally, insert the T-nuts in the knobs, and attach them to the router jig.

This is what the finished router dado jig looks like.

How To Cut a Dado with a Router
There are multiple ways how to use a router dado jig. You can cut dadoes, grooves, rabbets, and even mortises.
- Cut Dadoes and Grooves – use the material to set the exact width of the dado or groove by inserting it between the dado jig base pieces and locking it down. Then place the router between the guide rails and cut the dado. This will create an exact width router dado cut for the material you used as a reference. This method is perfect for making dado joints.
- Cut Rabbets – Use only one base piece of the dado jig to cut rabbets. Draw a line on the piece you want to cut place the edge of the jig along the drawn line, clamp it down and make the cut.
- Cut Mortises – Set the width between the base pieces as necessary and cut mortises. It is not as convenient as a jig designed specifically for cutting mortises, but it will do the job.
Tips for Cutting Dadoes with a Router Dado Jig
Secure Small Pieces: For cutting smaller pieces, use double-sided tape to firmly hold the material in position, preventing any unintended movement.
Steady Fixation: Ensure stability by clamping both the jig and the workpiece securely to a workbench while using the jig.
Maintain Alignment: Keep the jig properly aligned and level with the workpiece to ensure straight and well-balanced cuts.






My Take
I love this router jig. This is an easy build and it will help you so much in the workshop. It is versatile and adjustable and it will help you in multiple different ways. You can use it to cut dadoes, grooves, rabbets, and even mortises.
I have been using this jig for a few years now and it is one of the best router jigs you can have in the workshop. So if you have a router or planning on getting one, you definitely need to add this jig to your gear.
One thing you could consider as a disadvantage is that this jig is built with/for one router bit only. If you would like to use a different size router bit you would need to use a separate jig.
As an upgrade, you can add extra stoppers that could be placed anywhere along the length of the track. This addon is perfect to make stopped dados and more accurate mortises. Check the build here – Adjustable router dado jig
DIY Router Dado Jig Video
If you want to see how it is done, watch the video below for a step-by-step guide on how to make an exact width router dado jig.
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RELATED: Also, check out these other Router Jigs and make a nice addition to your workshop.
- A router circle cutting jig for cutting perfect circles
- An adjustable router template guide to accurately and precisely cut specific shapes in the stock.
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I hope the information shared in this blog post inspired you and now you are adding this router jig to your next builds. 😉