Choosing the right door hardware follows a set of established best practices. Here’s how to do it manually:

1. Determine Hinge Count: Start with two hinges for any door. Add a third hinge if the door is taller than 60 inches. Add a fourth hinge if the door is over 90 inches tall or exceptionally heavy (over 60 lbs). Exterior doors should always have at least three hinges.
2. Select Hinge Size: For standard interior doors (1 3/8" thick), 3.5" hinges are common. For thicker exterior doors (1 3/4" thick) or heavy doors, 4" hinges are required for adequate support.
3. Determine Handle Placement: The standard height for a door handle or knob is 36 inches from the finished floor to the center of the handle.
4. Choose the Backset: The backset is the distance from the edge of the door to the center of the bore hole for the handle. The standard for 1 3/8" thick doors is 2 3/8", while 1 3/4" doors typically use a 2 3/4" backset.

• Hinge: A jointed device on which a door, gate, or lid swings.
• Backset: The distance from the edge of the door to the center of the hole for the lockset or handle.
• Bore Hole: The large hole drilled through the face of the door where the main body of the lockset is installed.
• Strike Plate: The metal plate installed on the door jamb that the latch bolt extends into to hold the door closed.
• Solid Core vs. Hollow Core: Solid core doors are filled with wood composite material and are heavy, offering better sound insulation. Hollow core doors are lightweight with a honeycomb cardboard interior.

"When installing door hardware, precision is everything. A slightly misplaced strike plate can cause a door to rattle, while a handle installed with the wrong backset will have an unprofessional gap. I always use a drilling jig for locksets. It's a template that clamps to the door and guides your drill bits perfectly for both the main bore and the latch hole. It's an inexpensive tool that guarantees your hardware will be installed in the exact right spot every single time, saving you from costly mistakes on an expensive door." - Professional Locksmith & Carpenter

Standard Hollow Core Interior Door (80" high, 1 3/8" thick):
The calculator will recommend 3 hinges (since it's over 60" tall), 3.5" in size. The handle should be at 36" high with a 2 3/8" backset.

Heavy Solid Wood Exterior Door (80" high, 1 3/4" thick):
Because it's an exterior door and thicker, the calculator will recommend 3 hinges, but upgrade the size to 4" for better support. The handle backset would be 2 3/4".

• Using Interior Hardware on Exterior Doors: Interior hinges and locksets are not coated to resist rust and will fail quickly when exposed to the elements.
• Incorrect Backset Measurement: This is a very common mistake that leads to the handle being too close or too far from the edge of the door.
• Forgetting to Mortise Hinges: On most doors, a shallow recess (mortise) must be cut so the hinge leaf sits flush with the edge of the door and jamb.
• Using Screws That Are Too Short: The screws that come with hardware are often short. For the top hinge on an exterior door, use at least one 3" screw that goes through the jamb and into the wall stud for added security.

• New Door Installation: Determining all the necessary hardware specifications for a new interior or exterior door.
• Door Replacement: Ensuring the new hardware is compatible with the existing door and frame.
• Home Renovation: Planning hardware needs for a whole-house renovation project.
• Custom Door Building: Sizing hardware for custom-built doors of non-standard dimensions or weight.