Step 1 Measure for the Replacement
Before removing or purchasing any door lock or knob, take measurements of the space where you plan to install the new doorknob and deadbolt. The following measurements should be taken:
- The diameter of the holes cut out of your door for the door lock
- The diameter of the hole under the plate and around the knob itself. This may require removing the existing lock set. Its typical diameter is 2 1/8 inches.
- The distance from the edge of the door to the center of the hole, typically called the setback. Its typical diameter is 2 3/8 or 2 3/4 inches.
In some cases, taking measurements may not be as smooth of a process.
- When needing to create or enlarge holes, you can purchase a hole saw set that includes hole saws and a guide to help you.
- Some older doors may not be thick enough for modern locksets, which will require you to add a custom cut plate or door reinforcer.
Nowadays, locksets often allow you to change the handedness or adjust the latch to either distance, so having to choose a knob with the same setback may not be an issue. If you’re looking for even more of an upgrade, you can consider smart or electronic door locks for greater security.