I have a closet that I am planning on putting a 5 ft bi-fold door in. It is framed in witht he sheetrock hung and everything. I am ready to hang my door. I have purchased the door jamb pieces, but do not know what size the opening needs to be. Any help would be appreciated.
You can't do it the way you've planned it. There are different types of bifold doors. Some are made to fit into a standard, framed opening. Others are made from standard doors and are put into a larger than standardly framed opening. You seem to be putting jambs into a previously unframed opening. You might not be able to find doors that will fit into this arbitrary space.
Supplying the exact opening dimensions(W & L) you originally have would help.
Also tell us what style doors you want to install.