Build a Door Hinging Jig for Perfect Hinge Mortises

How to Build and Use a Door Hinging Jig for Perfect Hinge Mortises Every Time

If you’ve ever tried to hand-chisel a hinge mortise and ended up with a door that swings crooked or gaps unevenly, you already know the frustration. Getting three hinges perfectly aligned on both the door and the door jamb — every single time — is one of those finishing carpentry tasks that looks simple but has a way of humbling even experienced woodworkers. The good news? A shop-made door hinging jig solves all of that in one shot. In this article, you’ll learn how to build your own plywood router jig for cutting hinge mortises, and then how to use it to get clean, consistent dadoes on doors and door jambs alike. The best part: the commercial versions of these jigs run $400–$500. Building your own costs a fraction of that and can be customized to suit the exact hinges you use most often.

Materials List

3/4-inch plywood (enough to cut strips approximately 20 inches long — you’ll need two or three pieces depending on your jig design)
1/8-inch U-shaped metal channel strips (available at most lumber yards or home improvement stores — used as guide rails on the jig surface)
Wood screws appropriate for 3/4-inch plywood assembly
Wood glue (optional, for reinforcing the jig assembly)
Scrap wood or test material (for dialing in your router depth before working on actual doors)

Tools List

Table saw or circular saw (for cutting plywood strips to size)
Router with a guide collar (also called a template bushing — this is essential; without it the router will be uncontrollable)
1/2-inch straight router bit
Clamps (at least two — one for each end of the jig to secure it to the door or jamb)
Tape measure and pencil
Hand chisel (for squaring up corners if you’re using square-shouldered hinges)
Drill/driver (for assembling the jig)
Marker or paint pen (for labeling the “top” of your jig)

Step-by-Step Instructions

Part 1: Building the Jig

Cut your plywood strips. Start by ripping two strips of 3/4-inch plywood to the same width. Each strip should be approximately 20 inches long. These strips will form the main body of your jig and provide the routing surface that your router collar will ride against. The key here is consistency — both pieces need to be the same width so your router sits flat and level.
Plan your hinge opening locations. Before you cut anything, lay out where your three hinge openings will sit along the jig. Standard door hinging places the top hinge 7 inches from the top of the door, the bottom hinge 11 inches from the bottom, and the center hinge roughly in the middle. Mark these positions on your plywood strips. You don’t need a continuous slot running the full length of the jig — you only need material removed right where each hinge mortise will be routed, so plan your openings accordingly.
Create the three hinge openings. At each of the three hinge locations, cut an opening in your jig that is slightly longer than the length of your hinge. This extra room is intentional — it allows your router collar to travel freely while the bit cuts the mortise. The width of the opening should match the width of your hinge, again accounting for the offset that your router collar adds. Take your time with this step and test-fit your router collar in the opening before moving on.
Attach the metal U-channel strips. Fasten the 1/8-inch U-shaped metal strips along the edges of the jig. These serve as the running surface for your router — the router’s base plate or collar rides along the top of these strips as you make your passes. Secure them firmly so there’s no flex or play.
Add the stop block. This is a critical part of the jig that makes it repeatable. Cut a piece of 3/4-inch plywood and screw it to the back (bottom) of the jig as a stop block. When you place the jig against the top of a door or jamb, this block registers the jig in exactly the same position every time. Without it, you’d have to measure and re-mark your hinge positions on every single door — which defeats the whole purpose of building a jig.
Label the top of your jig clearly. Use a marker or paint pen to write “TOP” on the end of the jig that aligns with the top of your door. This sounds like a small thing, but when you’re on a job site working quickly, it’s easy to flip a jig and cut mortises in the wrong location. Labeling it takes two seconds and saves a ruined door.

Part 2: Using the Jig

Install the guide collar on your router. Before you do anything else, make sure your router collar (template bushing) is properly installed. This collar fits around the router bit and rides against the inside edges of your jig openings. Without the collar, the router bit has nothing to reference and will wander freely — the collar is what makes this whole system work.
Chuck in a 1/2-inch straight router bit. A 1/2-inch straight bit is the right choice here — it’s wide enough to clean out the mortise efficiently without requiring too many passes, and it’s strong enough to handle plywood and door stock.
Dial in your depth on scrap material first. This step is non-negotiable, especially for beginners. Set your router bit depth so that it cuts a recess equal to the thickness of your hinge leaf — nothing more, nothing less. If the mortise is too shallow, the door won’t close flush. Too deep and you’ll have a gap. Use scrap material that matches your door stock and test until the hinge leaf sits perfectly flush with the surface. Take notes on your depth setting so you can repeat it.
Position the jig on the door. With your test pieces done and your depth set, it’s time to work on the actual door. Place the jig so that the labeled “TOP” end is flush with the top of the door. The stop block on the back of the jig should be sitting underneath the door edge or against the door face, depending on your design. This registers everything automatically.
Clamp the jig securely. Apply one clamp at the top of the jig (near the top of the door) and one clamp at the far end to make sure the jig doesn’t shift during routing. Any movement while the router is running will result in a sloppy mortise, so don’t skip or rush this step.
Route the first hinge mortise. Set your router collar in the first hinge opening and begin routing. Work in a back-and-forth motion, making sure you cover the full area of the opening. Keep the collar in contact with the edges of the opening at all times. Take multiple passes if needed, working your way down to your final depth gradually. Don’t try to hog it all out in one pass.
Repeat for the center and bottom hinges. Move the router to the center hinge opening and repeat the same back-and-forth routing motion. Then do the same for the bottom hinge. By the time you’re done, all three mortises should be identical in depth and position.
Square up the corners if needed. Router bits leave rounded corners. If you’re using hinges with square corners (rather than rounded ones), use a sharp hand chisel to pare the corners square. Work carefully and take light cuts — you just need to remove a small amount of material in each corner.
Repeat the entire process on the door jamb. Use the exact same jig setup on the door jamb. Because you’re using the same jig registered to the same reference point (the top), the hinge mortises on the jamb will align perfectly with the mortises on the door. This is the real payoff of a well-built jig.

Pro Tips

Never skip the test cuts. The builder of this jig is emphatic about this: always rout a few test mortises on scrap before touching your actual door. Getting the depth dialed in is the most critical variable in this whole process, and scrap wood is cheap compared to a new door.
The guide collar is not optional. Without the router collar installed, your router has no way to follow the jig’s edges, and the bit will cut wherever it wants. Make sure your collar is snug and properly seated before every use.
Build your jig to match your hinges. This jig is designed around standard residential hinges. If you use different hinge sizes, you’ll need to adjust the openings in the jig accordingly. Take the time to build the jig right for your specific application — a jig that’s off by even 1/16 inch will drive you crazy over a full day of hanging doors.
The center hinge is worth it. Some folks skip the center hinge to save time, but the experienced finisher in this video always installs it for added door stability and support. Especially on heavy or solid-core doors, that center hinge makes a real difference in how the door hangs and operates over time.
Label everything and keep it consistent. Marking “TOP” on your jig isn’t just a good idea — it’s essential for making sure every door and jamb gets mortises in the same location. Consistency is what separates a professional-looking installation from one that looks cobbled together.

Frequently Asked Questions

What size router bit should I use with this jig?

The video recommends a 1/2-inch straight router bit. This size gives you good coverage on each pass without being so large that it’s hard to control. It pairs well with a standard guide collar and makes quick work of cleaning out the mortise area.

Do I need a guide collar, or can I just use the router’s base plate?

You absolutely need a guide collar for this jig to work properly. The collar rides against the inside edges of the jig openings and controls exactly where the bit cuts. Without it, your router bit will have no reference edge and will cut outside the mortise area. Don’t attempt this without the collar installed.

Can I use this jig for hinges with square corners, or does it only work for rounded hinges?

This jig works for both types. For rounded-corner hinges, the router does all the work and you’re done. For square-corner hinges, you’ll need to follow up with a hand chisel to pare the corners square after routing. It only takes a minute or two per mortise and the results are very clean.

How do I know what depth to set the router bit?

The mortise depth should exactly match the thickness of your hinge leaf — meaning when the hinge is set in the mortise, it sits perfectly flush with the surface of the wood. The best way to nail this is to hold your hinge against the router bit depth stop, set it to match, and then test on scrap until you’ve confirmed it’s exactly right before routing your actual door.

Will this jig work for all door sizes?

This particular jig is built around standard residential door hinge spacing. As long as you’re working with standard doors and standard hinges, it will work perfectly. If you’re working with non-standard doors, custom cabinetry, or unusually sized hinges, you’d want to build a jig tailored to those dimensions — but the same basic design and principles apply.

Conclusion

Building a shop-made door hinging jig is one of those projects that pays for itself the first time you use it. What used to require careful measuring, repeated test-fitting, and a lot of careful chisel work becomes a quick, repeatable process that turns out professional results every time. The jig itself isn’t complicated — a couple of plywood strips, some metal channel, a stop block, and a careful layout is really all it takes. Once it’s built, you’ll wonder how you ever hung a door without it. Take the time to do a few test cuts, get your depth dialed in, and let the jig do the work. Your doors will hang straight, your hinges will line up perfectly, and you’ll have a tool in your shop that’ll serve you for years. Now get out there and start routing.