When installing a door, which measurement is crucial for ensuring the door fits properly?

The width of the jamb is crucial for ensuring that the door fits properly because it determines how much space is available for the door to swing open and close correctly. If the jamb is too narrow, the door may not fit within the frame properly, leading to a situation where it may bind or rub against the frame. Conversely, if the jamb is too wide, it can create gaps that affect the door's functionality and security.

While other measurements, such as the height of the frame, the thickness of the wall, and the distance from the floor to the base trim, are important in the overall installation process, they do not directly impact the fit of the door within the jamb as significantly as the width of the jamb does. The jamb width ensures that the door has adequate clearance and contributes to a snug fit, which is essential for proper operation and aesthetics.