Wall Framing Calculator
Studs and plate lumber for framing a wall at 16 or 24 inch spacing.
Input sheet
DIY at your own risk. Calcora's calculators and guides are general estimates and information only — not professional, engineering, legal, or safety advice. Always verify local building codes and permit requirements, and hire a licensed pro for electrical, gas, plumbing, structural, or any work you're not fully comfortable doing yourself.
Framing lumber is the one material you never want to run short on mid-wall — a missing stud stops the whole line. This calculator turns a wall length and stud spacing into a stud count and the plate lumber to go with it, so one trip to the yard covers the layout.
How it works
Studs = wall length ÷ spacing, rounded up, plus one end stud. Each opening adds ~2 studs for kings and jacks. Plates run 3× the wall length (single bottom, doubled top).
Stud count follows the layout math carpenters use on the plate: divide the wall length in inches by the on-center spacing, round up, and add one stud for the far end. A 20 ft wall at 16 in on center needs 15 layout positions plus the end stud — 16 before openings.
Openings are where simple math undercounts. Every door or window gets king studs running full height on both sides and jack studs under the header, which more than replaces the common studs the opening removes. The calculator adds two studs per opening as a working allowance; complex openings with cripples above and below can eat a third.
Studs = (wall length in inches ÷ spacing, rounded up) + 1 end stud + 2 per opening. Plate lumber = wall length × 3 (one bottom plate, doubled top plate).
Worked examples
A 20 ft interior wall at 16 in on center with one door. → 18 studs and 60 linear feet of plate stock.
240 ÷ 16 = 15, plus one end stud is 16, plus 2 for the door opening = 18. Plates run 20 × 3 = 60 ft.
A 24 ft garage wall at 16 in on center with a window and a door. → 23 studs and 72 linear feet of plates.
288 ÷ 16 = 18, plus one end stud is 19, plus 4 for two openings = 23. Plates: 24 × 3 = 72 ft.
Tips & gotchas
- Buy two or three extra studs per wall — crowned, bowed, or split boards in the lift are a given, and culling them beats straightening them.
- Corners and wall intersections take extra studs beyond this count (two or three per corner depending on the detail) — add them per corner in your plan.
- Use straight, dry stock for plates; a crowned plate telegraphs a hump into the whole wall.
FAQ
Should I frame 16 or 24 inches on center?
16 in OC is the standard for load-bearing walls and anything holding drywall. 24 in OC saves lumber on non-bearing partitions where code allows it.
Why is the top plate doubled?
The second top plate ties intersecting walls together and stiffens the wall between studs. Single top plates are allowed in some non-bearing cases, but doubled is the default framers expect.
Does 24 in on center save much?
About a third of the studs. It is fine for non-bearing partitions and common in advanced framing, but check code for bearing walls and use 5/8 in drywall to avoid wavy walls.
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