How Are Internal Doors Measured?

To determine the size of your door, take a few measurements and do some basic math. Find the height and width of the door slab, which is the actual door without any frame or hardware. If you plan to only replace the door and keep the frame as is, then take accurate and detailed measurements of the door’s rough opening and door jamb.

To measure the door’s size, first find the width by measuring from the left corner of the door to the right corner. Then, measure the height by running your tape measure across both vertical sides of the frame. Measure the door jamb width by measuring from the backside of the trim to the backside of the interior trim.

Replace an interior door to improve the look and functionality of your space, and increase your property value. Follow this guide on how to measure and install prehung interior doors for replacement. Proper measurements are critical to getting the right door the first time. Prehung doors are much easier to install, so it is essential to follow this guide on how to measure a door for a successful installation.