Step-by-Step Measurement Guide

Step 1: Measure Height

This is the simplest measurement. Simply use a ruler or tape measure to measure the length of the Hinge from top to bottom.

· Result: This is the hinge height (e.g., 3 inches, 3.5 inches, 4 inches).

Step 2: Measure Single Door Panel Width

This is the most critical and commonly misunderstood measurement.

1. Fully extend the hinge to a straight position.

2.Measure from the center point of the hinge pin to the outer edge of the single door panel.

·  Result: This is the single door panel width. Common specifications are 1.5 inches for interior doors and 2 inches for exterior doors.

Step 3: Calculate the Opening Width

Once you have the single door panel width, calculating the opening width is straightforward:

· Opening Width = (Single Door Panel Width) × 2

· Example: If each door panel is 1.5 inches wide, the opening width is 3 inches.

Common Misconception: Never directly measure the total opening width and call it the “door panel width.” In the hardware industry, ‘width’ specifically refers to the size of a single door panel. If you order “3-inch hinges,” the hinges you receive will typically have an opening width of 3 inches (meaning the single door panel width is 1.5 inches).

How to Specify Hinge Dimensions

When ordering or inquiring about hinges, use the height × width specification format.

· Example: A hinge with a height of 3.5 inches and a leaf width of 1.5 inches is referred to as a 3-1/2“ × 1-1/2” double-action hinge. Its opening width is 3 inches.

Additional Important Factors

Besides the core dimensions, you should also check these:

1.Knuckle Length: The length of the cylindrical part. This should match the height of the hinge.

2.Pin Diameter & Type: Is the pin removable? (Usually, yes). For heavy doors, a ball-bearing hinge with a larger pin is better.

3.Radius Corner vs. Square Corner: This refers to the shape of the leaf where it meets the knuckle. You must match the corner type of your existing hinge mortise, or it won't fit correctly.

· Radius Corner: Has a rounded corner.

· Square Corner: Has a sharp, 90-degree corner.

4.Screw Hole Quantity & Placement: Count the number of screw holes on each leaf (typically 3 or 4). While not a deal-breaker, matching this looks more professional.

5.Material & Finish: Note if the hinge is steel, brass, bronze, etc., and its finish (e.g., polished brass, satin nickel, oil-rubbed bronze).

Pro Tip for Replacing Hinges

The safest way to ensure a perfect match is to take the old hinge with you to the hardware store. This eliminates any guesswork and allows you to compare all the physical attributes side-by-side.