How to Measure Cabinet Doors and Drawer Fronts:
If you want your new doors and drawer fronts to fit like your old ones, then you can order your new doors and drawer fronts in the same sizes as the old ones that you are replacing.
If you do not have old or existing doors or drawer fronts, then you will have to decide how much of the cabinet face frame you want your new doors and drawer fronts to overlap. Then, you add this dimension to the opening size the door or drawer front will cover when it is installed.
For example, if you decide to cover 1/2" of face frame all the way around the perimeter of a door or drawer when that door or drawer is closed, then you would add one inch to the height and width dimension of the opening that the new door or drawer front is going to cover. When you install the door or drawer front, if you center it over the opening it should overlay the face frame 1/2" all the way around the perimeter of the opening it covers.
Of course, if you prefer to change the overlay, you may do so as long as you leave enough room between adjoining doors and drawer fronts so that they can still function.
An exception to calculating this rule would be double doors.
A cabinet with butt doors is one that has both a left and a right door with no center mullion between the two. In this case, if you wish to use a 1/2" overlay on a cabinet with a 30-inch opening, you would add 1/2" to each door. You arrive at this number by starting out with the idea that you want to maintain a 1/8" gap between the two doors when they are shut. Therefore, you add 1/2" to each side and use the adjustment in the hinges to create the gap. This results in ordering two doors both sized 15-1/2" wide to cover a 30" wide cabinet opening and butt together leaving a 1/8" gap in the middle.
All cabinet door or drawer measurements can be made to the 1/16 of an inch.
How to Measure Double Doors.
Measure the Width and Height of the inside of the cabinet frame. Measure it in inches to the sixteenth of an inch.
** Very Important **
From your measurements - width and height of the cabinet frame opening.
ADD 1 inch to the width and the height. THEN divide ONLY the Width measurement in half and order 2 doors of that size.
Cabinet Frame Opening - 36" Wide x 26" High
ADD 1 inch to each dimension - So, new dimensions will be 37" x 27"
Then Divide 37" in half - New width dimension will be 18.5"
You would then order 2 Doors of 18.5" width x 27" height doors
How to calculate square footage:
Calculated square footage is equal to width to the next whole inch and height to the next whole inch.
sqft. = Width(rounded to whole inch) x Height (rounded to whole inch) / 144