Make a Dado Jig for Router (Step-by-Step Guide)

Make a dado jig for router that will help you make accurate and precise dadoes, grooves, and rabbets.

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. 

Cut dados, grooves and rabbets with a dado jig for router.
How to cut an exact width dado with a trim router

The dimensions of this jig are 700 x 200 mm, providing about 500 mm of space for cutting dadoes, which will vary based on the size of your router base. I designed the dado jig specifically for a DeWalt plunge router, but the principles can be adapted to fit any router.

This project is great for beginners, needing just a few basic tools to complete. For a closer look at the jigs I utilized during the build, make sure to check out the end of this article.

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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Table of Contents

  1. Router Dado Jig Video
  2. Router Dado Jig Plans PDF
  3. Materials and Tools you will need
  4. General Questions
    1. How difficult it is to build?
    2. What is the difference between a dado and a groove?
    3. What is the difference between a dado and a rabbet?
    4. Which router dado bit should I use?
  5. Step1: Make the Router Jig Base Unit
    1. Attach the First Guide Rail
    2. Attach the Second Guide Rail
  6. Step 2: Assemble the Router Dado Jig
    1. Fix Both Base Pieces Together
    2. Make Wooden Knobs
  7. How to Cut a Dado with a Router
  8. 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 when using any power tool.

DIY Router Dado Jig Plans

Download the Router Dado Jig Plans here
Router Dado Jig Plans PDF, Router Dado Jig Plans, Plans for Dado Jig

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

Check all the Tools I Use

Trim Router –
Circular Saw –
Jigsaw –
Hand Drill –
One Hand Clamps –
Spring Clamps –
Machinist Square / Speed Square
Center Hole Punch –
Marking Gauge –

Router Bit Set –
Chisel Set –
Wood Glue –
Double-Sided Woodworking Tape –
2x M6 Bolts – 35 mm, M6 T-nuts
Forstner bits – 10mm, 15mm –
Hole saw – 38/40mm –
Sand Paper / Sanding Wheel

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Durable motor delivers the power to meet the toughest applications

How difficult it is to make a router dado jig?

This project is perfect for those just starting out in woodworking and is a key jig to have for anyone working with a router. Building the jig isn’t complicated; the process is direct, and you can have the entire dado jig ready in just one day.

Check out the list of materials needed for this project. In addition to these, you’ll need a router, and possibly a jigsaw or another power tool to handle 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.

Table Saw Rabbet Cut. How to cut a rabbet.
Cutting a rabbet on a table saw

What dado router bit to cut dadoes and grooves?

When cutting dadoes and grooves, you can choose between two types of router bits:

  1. Straight bit – a double flute straight router bit is a versatile choice that works well for most materials, providing great results.
  2. Spiral Bit – For cleaner cuts, you can opt for a spiral router bit (upcut/downcut). 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.

Smooth and precise cut. Exceptional chip ejection to allow cleaner cutting

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 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 chose MDF for the base piece because it’s straight and allows the router to glide smoothly over it. Its 5 mm thickness is enough to attach the guiding rails securely, while also not consuming too much of the router bit’s length. HDF or a 6mm plywood sheet would work just as well for this purpose.

Router Dado Jig - cutting the main base piece

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.

Router Dado Jig - measuring and cutting aluminum guide rails
Router Dado Jig - Cutting aluminum guide rails

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).

Router Dado Jig - drilling holes in guide rails
Router Dado Jig - Attaching guide rails to router jig base piece
Router Dado Jig - Attaching guide rails to router jig base piece

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’ve chosen a ø6mm bit for my work. Since I frequently make smaller cuts, a 6mm router bit suits my needs perfectly.

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.

Router Dado Jig - Setting the right width between the guide rail and the router bit

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. 

Router Dado Jig - Aligning the router front with the router base piece

2. Attach the Second Guide Rail

Repeat the same process for the second base piece. 

  1. Attach the aluminum L angle, leaving space for clamping.
  2. Cut the wood excess using the other side of the router. Mark the base piece with the letter B.
Router Dado Jig - Attaching guide rails to router jig base piece
Dado Jig For Router - Cutting wood excess from the other router base piece

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

Dado Jig For Router - Front and back router base piece of the router dado jig

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

Dado Jig For Router - measuring the width of the router jig base piece

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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.

Dado Jig For Router - Cutting router jig stoppers
Dado Jig For Router - Attaching stoppers to the ends of the router jig

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

Dado Jig For Router - Attaching stoppers to the ends of the router jig

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

Dado Jig For Router - Inserting a bolt in one of the router jig end stoppers
Dado Jig For Router - Bolts inserted in a wood piece

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

Dado Jig For Router - Attaching a stopper with a bolt on the router jig base piece

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.

Dado Jig For Router - Attaching both router jig base pieces together
Adjustable Router Jig - cutting a slot with a dado jig
Dado Jig For Router - A finished router dado jig for making dadoes, grooves and rabbets.

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:

  1. Mark the circumference of the knob using a 38mm saw hole.
  2. Drill 10mm holes every 60 degrees. That will make a six-pointed star knob.
  3. 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
  4. Cut out the knob with a saw hole.
Dado Jig For Router - Making a six star wooden knob
Dado Jig For Router - Making a six star wooden knob

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

Dado Jig For Router - Sanding wooden knobs

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

Dado Jig For Router - A six star wooden knob

This is what the finished router dado jig looks like.

Router Dado Jig - A completed adjustable router dado jig ready for use.

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.

  1. 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.
  2. 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.
  3. 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

  1. Secure Small Pieces: For cutting smaller pieces, use double-sided tape to firmly hold the material in position, preventing any unintended movement.

  2. Steady Fixation: Ensure stability by clamping both the jig and the workpiece securely to a workbench while using the jig.

  3. Maintain Alignment: Keep the jig properly aligned and level with the workpiece to ensure straight and well-balanced cuts. 

Adjustable Router Jig - setting the width for the dado
Router Jig - cutting a dado with a router jig
Router Jig - making a dado joint with a router dado jig
Router Jig - making a dado with a dado jig
How to cut dadoes and grooves with a router. DIY Router dado jig.
How to cut dadoes with a router. DIY Router dado jig.

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

RELATED: Also, check out these other Router Jigs and make a nice addition to your workshop.

  1. A router circle cutting jig for cutting perfect circles
  2. An adjustable router template guide to accurately and precisely cut specific shapes in the stock.

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An Adjustable Router Dado Guide Jig for cutting exact width dados and grooves and making dado joints.

I hope the information shared in this blog post inspired you and now you are adding this router jig to your next builds. 😉

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About the author, Lukas
About the author, Lukas

Meet the creator of AllFlavor Workshop! As a passionate DIYer and woodworking enthusiast, Lukas is always looking for ways to make things himself rather than buying them off the shelf. With a keen eye for design and a knack for working with wood, Lukas enjoys sharing his craft with others and helping them discover the joy of building. Whether you're an experienced woodworker or a novice looking to try your hand at a new hobby, you're sure to find plenty of inspiration and tips on AllFlavor Workshop.