Stud calculator for wall framing
This stud calculator turns a wall length and height into a framing list: layout studs at 12, 16, 19.2 or 24 inches (or 400, 450, 600 mm), king and jack studs, headers, cripples, window sills, plates, blocking and sheathing sheets. Add each door and window as a rough opening and the calculator removes the layout studs that fall inside it and adds the studs that frame it.
It is a stud calculator with doors and windows for walls, garages and sheds. For a quick board-foot total of studs and plates on a plain wall the board foot calculator has a simple wall mode; this page goes further by framing openings, corners, blocking and sheathing. Everything runs in your browser.
It counts lumber for standard platform framing. It does not size structural members: the header size you choose, the number of jack studs and the bracing are set by your building code or engineer.
How to use the Stud Calculator (Wall Framing)
- Enter the wall length and the wall height from floor to the top of the plates, then choose the stud spacing and stud size.
- Set the number of three-stud corners, the plate lines (3 for a bottom plate plus double top plate) and the plate stock length.
- Add each door and window with its quantity and rough-opening width and height; windows also need the sill height from the floor.
- Pick the header lumber, any rows of blocking, the sheathing sheet size, sides and waste allowance.
- Read the cut list, copy it or download the CSV, and take it to your lumber yard.
Stud Calculator (Wall Framing) features
Openings framed properly
Kings, jacks, a two-member header, cripples above and below and a sill for each opening.
Layout studs adjusted
Studs that fall inside an opening are dropped from the count.
Corners and plates
Three-stud corners and plate pieces from your stock length.
Blocking and sheathing
Rows of blocking and the 4 × 8, 4 × 9 or 4 × 10 sheets for one or two sides.
Cut list export
Copy or download a CSV with each piece, quantity and cut length.
How the studs are counted
The layout count is wall length ÷ spacing, rounded up, plus 1. A 20 ft wall at 16 in is 240 ÷ 16 = 15, plus 1 = 16 studs. Stud cut length is the wall height minus the plates: with 3 plate lines at 1½ in each, an 8 ft wall (96 in) gives 91.5 in studs; precut 92⅝ in studs are meant for a framed height of 97⅛ in (three plates plus 92⅝ in), which leaves an 8 ft ceiling after the drywall, so enter 8.094 ft if you are using them.
Each opening then adds 2 king studs (full height), 2 jack studs under the header, a header of two members that is the rough width plus 3 in, and cripples between the header and the top plate. A door of 38 × 82 in and a window of 36 × 48 in with a 36 in sill on that wall remove 2 layout studs each, add 4 kings and 4 jacks, and bring the total to 20 full-length studs. Windows also need a sill and cripples below it. Each three-stud corner adds 2 studs to the end stud already counted.
Typical rough openings
Rough openings are about 2 in wider and 2 in taller than the door unit; windows use the maker's stated rough opening. These are common sizes, so use the manufacturer's data for the real unit.
| Opening | Rough width | Rough height |
|---|---|---|
| Interior door 30 in | 32 in | 82 in |
| Exterior door 36 in | 38 in | 82 in |
| Window 3 × 4 ft | 36 in | 48 in |
| Double window 5 × 4 ft | 60 in | 48 in |
What this does not decide
- Header depth and the number of jacks depend on the span, load and local code (for example the IRC header tables). The calculator uses the lumber you pick; it does not check it.
- Fire blocking, seismic and wind bracing, hold-downs and structural sheathing nailing are outside this list. Blocking is counted as a simple row between layout studs.
- Waste on studs is not added; buy a few spare studs, since lumber is often bowed. For the sheet goods inside, see the drywall calculator, and for exterior cladding the siding calculator.
Stud Calculator (Wall Framing) FAQ
How many studs do I need for a wall?
Divide the wall length by the stud spacing, round up and add 1. A 20 ft wall at 16 in on centre needs 16 layout studs before corners, doors and windows.
How many studs for a wall with a door?
A door removes the layout studs inside its rough opening and adds 2 king studs and 2 jack studs, plus a header and short cripples above it. A 38 in rough opening removes 2 layout studs and adds 4, so the net gain is 2 studs.
How do I frame a shed wall?
Use 2 × 4 studs at 16 or 24 in, a bottom plate and double top plate, a three-stud corner at each end, and a header over each opening. Enter the wall once per length, or add the walls together for a quick total.
What are king studs and jack studs?
King studs run full height on each side of an opening. Jack (trimmer) studs sit against them and carry the header, ending under it.
What size header do I need?
It depends on the opening width, the load above and your code. Small non-load-bearing openings can be flat 2 × 4 or 2 × 6; load-bearing ones use tabulated or engineered headers. Pick the lumber here and confirm with your code.
Should I use 16 or 24 inch spacing?
16 in is the standard for most framing and gives stiffer walls; 24 in saves lumber where the code and loads allow it. Always check span limits for the sheathing and cladding.