How a door or window opening is framed — king, jack, header, and cripple studs
Every opening is framed the same way: king studs tie it to the wall, jacks carry the header, and cripples fill above the header and below the window sill. The rough-opening width/height are your inputs; the header size comes from the IRC R602.7 table.
What this diagram shows
A wall elevation showing the parts that frame an opening. Full-height king studs on each side tie the opening into the wall. Shorter jack (trimmer) studs inside the kings carry a built-up header that spans the opening and routes the load down to the jacks. Cripple studs fill the short space above the header, and for a window a rough sill with cripple studs below it closes the bottom of the opening. The rough-opening width and height are the dimensions you enter; the header size comes from the IRC R602.7 span tables.
Stud Wall Framing Calculator
Size studs, plates, headers, cripples & nails for 2x4 / 2x6 walls. Per 2021 IRC R602.3, R602.7 header spans & R602.3(1) nailing. Free, no signup.
Related diagrams
Framing & StructureHow many studs a wall needs — spacing sets the count (length ÷ spacing + 1)
