Note: Door measurements are always given width first, then height.
Step 1: Take a picture of the door and print it out, or draw a rough diagram. Take it (or draw it) from the exterior view. Appropriately indicate the hinges and handle/knob and you will know which way it hangs.
Step 2: Label it a right- or left-hand door and in-swing or out-swing just to be safe.
Step 3: Use the printed diagram to write the appropriate measurements – Now you can take a measurement of the width, height, and thickness, or edge, of the door. Make sure you do not include any other features, like weather stripping or the door sweep. ONLY measure the door. Write down the exact measurements and, in parentheses, round them up to the nearest inch.
Step 4: Measure the width of the door jamb. Again, do not measure any of the trim materials. When you face the jamb, you will take the measurement from the back of the interior trim piece to the back of the exterior trim piece.
Step 5: To be on the safe side, it’s worth measuring the height and width of the framed door space – not including any trim materials.
Now you’re an expert in how to measure a door for replacement. Your accurate measuring techniques will help you and the customer service representative to choose a door that will fit perfectly the first time you install it.