How to Enlarge a Hole for a Doorknob

A doorknob is the handle used to open and close doors.

On most doors, you have a doorknob on both the inside and the outside so you can operate the door from either direction. When you need to replace a doorknob, you might find the existing doorknob hole is simply too small. That means you'll need to enlarge a hole for the doorknob before you can install your new knob.

Cut a ½-inch thick piece of plywood so it's six inches wide and eight inches long.

Place your new doorknob template, which should be included with your doorknob set, on the piece of wood. Mark the appropriate areas of the template onto the plywood.

Use a hole saw to drill through your piece of plywood to create your own wooden template.

Measure the backset on your existing doorknob hole. The backset measures the distance between the edge of the door and the center of the existing doorknob hole. It should be either 2 3/8-inches or 2 3/4-inches.

Clamp the plywood template to your door so it's in the exact position where you need to enlarge the doorknob hole.

Before you drill with your hole saw, make sure you have the same backset as you measured previously, either 2 3/8-inches or 2 3/4-inches from the edge of the door. This will help ensure the hole in the guide is the correct distance from the edge of the door.

Drill about half way through the door using your hole saw.

Position your plywood template on the other side of the door. Make sure you have this template exactly opposite where you drilled in Step 7. Drill again with your hole saw until the two holes meet in the middle.

Things You Will Need

  • ½-inch thick plywood
  • Doorknob template
  • Hole saw
  • Tape measure
  • Clamps
  • Doorknob


  • If the doorknob hole is only slightly too small for your new doorknob, use a small course file to file down the area you need enlarged.

About the Author

Kristan Hart is an award-winning journalist in Springfield, Mo., who provides SEO web copy as a freelance writer/editor. She has a decade of experience and holds a bachelor's degree in mass communications with an emphasis in broadcasting.