How to Frame a Door Width

Measure the width of the door. Add 2 inches to the measurement. Cut this length from the bottom plate in the location where you plan to put the door.

Measure the distance between the top plate and bottom plate in the wall frame. Cut the king studs to this length.

Place the king studs vertically on either side of the door opening, 1 1/2 inches away from the cut in the bottom plate. Nail the king studs into place. Use metal connector brackets to ensure that the king studs are positioned at 90-degree angles to the bottom and top plate.

Measure the height of the door with your measuring tape. Add 1 inch, then cut the jack studs to match this length.

Nail each jack stud to a king stud so that the jack stud is flush with the edge of the doorway you cut in Step 1. The bottom of each jack stud should rest on the bottom plate.

Measure the distance between the king studs, and cut the header to this length. If this door is being installed in a load-bearing wall, check the plans for the dimensions of the lumber to use for the header. If the wall is not load-bearing, use a standard 2-by-4 piece of wood.

Place the header horizontally between the king studs. The header should be resting on top of the jack studs. Nail the header into place, using metal connector brackets to connect the header to the king studs.

Measure the distance between the header and the top plate. Cut two pieces of lumber, called cripple studs, to this length. Nail the cripple studs into place between the header and the top plate. Space the cripple studs 12 inches apart, centered above the doorway. Use metal connector brackets to ensure that the cripple studs are positioned at 90-degree angles to the header and top plate.