How to Cut Off Bi-Fold Doors

Twist the screws in the bi-fold door's hinges counterclockwise with a screwdriver. Loosen and remove the screws from the door's hinges. Remove the hinges from the door's frame.

Latch a tape measure onto the door's side. Align the tape with the door's top rail. Stretch the tape to the opposite side of the door. Mark the desired width of the door on the door's top rail with a pencil. Stretch the tape across the door's bottom rail and create a similar mark.

Draw a chalk snap line between the width marks, pull the chalk line's string taut and snap the line to lay out a cut mark across the door's height. If the door is louvered, make equal cuts on each side of the door by "splitting the difference." In other words, divide the desired reduction in width by two and mark half on each of the door's opposite side rails, called stiles.

Latch the tape onto the door's top rail and position the tape near the rail's corner. Stretch the tape to the door's bottom rail and mark the desired door height. Move the tape to the opposite corner of the top rail, stretch the tape to the bottom rail and mark desired height on the opposite side of the bottom rail. Stretch a chalk line between the corresponding marks, pull the line taut and snap the line to lay out a cut line across the width.

Attach a finish blade to the circular saw. Set the saw's base on the edge of one of the door's stiles. Align the blade with the width cut line that runs along the stile. Activate the saw and cut through the width line to cut the door to the desired width. Align the saw with the height line that runs across the door's bottom rail. Activate the saw and push the saw through the line to cut the door to the desired height.