How To Replace An Old Door Knob With The Wrong Size Hole (Picture Tutorial!)

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Last updated on February 29th, 2024 at 04:55 pm

Wondering if you can resize an old door knob so a modern one can fit into the hole? Well, look no further because I have your answer!

Old doors with smaller door knobs can easily be resized using a door lock installation kit that includes the templates and hole saws for a larger door knob hole and latch hole. Once the holes are resized, any modern-day door knob will fit properly.

Now that we’ve got the basics out of the way, let’s break into the details further so you can easily resize the old door knob hole into a bigger hole.

Let’s dive in!

Quick Navigation: How To Resize An Old Door Knob That’s Too Small

  1. Remove The Old Door Knob
  2. Put Painter’s Tape Over The Old Hole
  3. Use The Hole Template & Large Hole Saw To Cut New Door Knob Hole
  4. Use The Hole Template & Small Hole Saw To Cut New Latch Hole
  5. Install New Door Knob
  6. Other FAQs About Resizing Small Door Knob Holes
  7. Final Thoughts

Level Of DifficultyTime To Complete
Easy30 Minutes
Material ListTool List
Broom & Dust PanRyobi Door Lock Installation Kit
Painter’s TapeDrill
New Door KnobSmall wood chisel (optional)

Step One: Remove The Old Door Knob

The first step to resizing an old door knob hole is to remove the old door knob.

Here’s what our old door knob looked like. We had to pop off the decorative plate against the door to access the screws and remove them.

It was kind of annoying because we completely destroyed the decorative back plate while removing it. But we didn’t need the old door knob, it ended up not being a big deal.

Once the door knob was off, we instantly noticed that the hole size was way too small for the new door knob we just bought.

So we decided to purchase this Ryobi Door Lock Installation Kit found at Amazon to make this job significantly easier.

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The kit comes with:

  • A jig template to cut both the door knob hole (cross bore) and the latch hole to the standard size – it works perfectly for wood or metal doors that are 1-3/8 to 1-3/4 inches thick
  • 2 bi-metal hole saws to cut both holes
  • And all of the other pieces you might need to install and resize a door knob, latch, and strike plate

Once we got the kit and some painter’s tape, we were able to complete the next steps in about 30 minutes with few difficulties.

Step Two: Put Painter’s Tape Over The Old Hole

The next step to resizing an old door knob hole is to put painter’s tape over the old hole.

I highly recommend you put painter’s tape over both sides of the door knob hole before sawing anything. We made the mistake of not doing this, and while sawing, the hole saw jumped.

It left behind an ugly scratch on a part of the door that the decorative back plate couldn’t cover. Once that happened, we took the door knob jig off and taped both sides.

The painter’s tape will help minimize any chipping or scratches while you’re sawing the new holes.

Once you’ve got painter’s tape on the door, take the door knob jig and set the thickness to the correct thickness for your door. There’s a little thickness lever on the bottom of the jig that needs adjusted.

Then slide the jig over the door and line the latch hole in the jig with the latch hole in the door and screw the jig into the door using the screws from either your old or new door knob latch.

Screwing the jig into the door will help keep the saws in the correct spot while you cut the door.

Here’s what the door knob jig looks like after it’s been aligned and screwed into place on the door.

I also recommend sawing from the outside of the door towards the inside of the room. If any of the door chips while sawing, most of the damage will be on the inside of the door (the less seen side) instead of the outside.

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With painter’s tape, the chipping shouldn’t really happen, but might as well take the extra precaution just in case.

You can flip the jig upside down or right-side up to set it up on whichever side of the door you want to cut through. For the side we wanted, we had to use the jig upside down.

Step Three: Use The Hole Template & Large Hole Saw To Cut New Door Knob Hole

The next step to resizing an old door knob hole is to cut the larger door knob hole.

Once the door knob jig is screwed into place, use the large hole saw and a drill to saw through the door.

Here’s what the backside of the door looks like while the hole is being cut. Without the painter’s tape, the hole saw would have chipped the surrounding wood pretty badly.

And here’s what the freshly cut door knob hole looks like after the jig is removed. It just cuts right overtop the old hole, so you can’t even tell it was resized!

Leave the jig on the door for the next step.

Step Four: Use The Hole Template & Small Hole Saw To Cut New Latch Hole

The next step to resizing an old door knob hole is to cut the larger latch hole.

Now, switch out the large hole saw for the small hole saw and cut the larger latch hole through the end of the door.

We like to leave the large hole saw in the door knob hole while cutting the latch hole to further help the door knob jig stay in place while cutting. (Sometimes it moves a little while sawing without this extra step and makes your holes out of alignment.)

Once both holes are cut, you can unscrew the jig from the door!

Here’s what the door looks like after both holes have been sawed.

Step Five: Install The New Door Knob

The final step to resizing an old door knob hole is to install the new door knob hole.

Now all you need to do is sweep up the mess from sawing and install the new door knob!

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You might have to use a wood chisel to chisel out some wood under the latch plate if the new one sticks too far off the door. But otherwise, you are all done and can admire your new door knob!

Other FAQs About Resizing Small Door Knob Holes

Here are some other frequently asked questions about replacing old door knobs to help you install your new modern door knob much easier!

Are All Door Knob Holes The Same Size?

All door knob holes are not the same size. Standard door knob and latch sizes used to be smaller on older doors. Modern-day door knobs are too large for the holes. These smaller holes can easily be resized using a door lock installation kit.

What Is The Standard Hole Size For A Door Knob?

The standard size door knob hole is a 2-1/8 inch diameter cross bore with a 1-inch diameter latch bore.

Final Thoughts On Resizing Small Door Knob Holes

There you have it!

Resizing a too-small door knob hole is simple when using a Ryobi door lock installation kit. If you plan to resize several door knobs, then I highly recommend purchasing this kit to make the job a breeze!

Hopefully, this tutorial helped you switch out your old door knobs.

Catch you in my next post!

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By Christine

Christine is a blogger and DIYer who tackles home renovation and decorating projects alongside her husband, Adam, for their personal residence and rental properties. Although she successfully tackles large renovation projects to avoid expensive contractor fees and bring her vision to life now, her path to success was not easy.

Go here to read her story,  From a Clueless First-Time Homebuyer To A Confident DIYer Creating Her Dream Home One Project At A Time.

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