Buying a smart lock only to find out it doesn't fit your door is a frustrating, avoidable mistake. Doors vary more than most people expect, both in how thick the door itself is and in how far the hole is set back from the edge. A few minutes with a tape measure before you buy saves a return and a reinstall.
The Two Measurements That Matter
Door thickness: This is how thick the door itself is, measured edge to edge where the knob will sit. The EMBENLY Secure Smart Door Knob is designed to fit doors between 30–50mm thick. Most standard interior and exterior doors fall within this range, but older homes or custom doors can sometimes be thicker or thinner.
Backset: This is the distance from the edge of the door to the center of the hole where the knob's spindle sits. The lock supports both common backset sizes: 60mm and 70mm.
How to Measure Your Door
- Thickness: Close the door and measure straight across its edge with a tape measure, from one face to the other.
- Backset: If you're replacing an existing knob, measure from the edge of the door to the center of the existing hole. If you're installing into a fresh door, this measurement is determined by where the hole is drilled.
Write both numbers down before you install anything.
What Happens If Your Door Doesn't Match
If your door's thickness or backset falls outside these ranges, the lock's included hardware may not seat properly, leading to a loose fit, a knob that doesn't turn smoothly, or a latch that doesn't align with the strike plate. This isn't a safety issue on its own, but it can make the lock harder to operate reliably over time.
A Few Other Things to Check Before Installing
- Existing holes: If you're replacing an older knob, check that the existing holes match a standard cross-bore pattern; most standard interior and exterior doors do.
- Door material: Solid wood, hollow-core, and metal doors can all typically accommodate a standard knob lock, but very thin hollow-core doors sometimes fall below the minimum thickness.
- Handedness: Most knob locks aren't handed (they work on doors that swing either direction), but it's worth checking your specific installation instructions if you're unsure.
If You're Not Sure
If your measurements are close to the edge of the supported range, or you're replacing a non-standard lock, it's worth double-checking with EMBENLY support at info@embenly.com before installing, especially if your door is part of a rental property where a bad fit means redoing the work.
The Bottom Line
Measure your door's thickness and backset before you install. If your door falls within 30–50mm thick with a 60mm or 70mm backset, the EMBENLY Secure Smart Door Knob should fit without any extra hardware or modification.
