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Stud Framing Calculator

Enter the wall length and spacing, then tell us about corners, intersections and openings. We count the field studs, add the standard framing allowances, and total the plate lumber too.

Diagram of a stud wall showing studs at even spacing with top and bottom plates
Studs stand at even spacing along the wall, with plates top and bottom.

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How studs and plates are calculated

Field studs are pure spacing geometry: wall length ÷ spacing, plus one for the end of the run. At 16 in on-center that's the estimator's shortcut of 0.75 studs per foot of wall, plus one. 24 in and 12 in spacing work the same way.

Allowances follow standard estimating practice: +2 studs per corner (a three-stud corner: one is the field stud already counted), +2 per wall intersection for backing, and +2 per opening as a basic king-and-trimmer allowance. Full practice puts a king and trimmer on each side of an opening (4 studs) plus header stock, so the +2 is a deliberate simplification. The waste allowance (10–15% in most published estimators) covers some of the difference, but add a couple of studs per ordinary opening and more for openings wider than ~5 ft to be safe.

Plates: one bottom plate and a double top plate (the standard detail in USDA Forest Products Lab framing guides) = 3 × the wall length in linear feet, converted to boards at the stock length you pick. Buying the lumber by volume instead? The Board Foot Calculator prices rough lumber by the board foot.

Sources

The figures behind this calculator come from published manufacturer data and industry standards:

Worked examples

24 ft wall, 16 in o.c.

19 field studs + 4 for the 2 corners + 2 for 1 opening = 25, +10% waste; plates 72 ft in 12 ft boards.

Buy 28 studs + 6 plate boards

12 ft wall, 24 in o.c.

7 field studs + 4 for the 2 corners = 11, +10% waste.

Buy 13 studs + 3 plate boards

40 ft wall, 16 in o.c.

31 field studs + 4 corners + 2 intersection + 6 for 3 openings = 43, +10% waste.

Buy 48 studs + 10 plate boards

Frequently asked questions

How many studs do I need for a 24 ft wall?
At 16 in on-center: 19 field studs. A real wall needs more. Corners, intersections and openings bring this example to 28 with waste, plus 6 boards for the plates. The spacing-only count is always the floor, never the order.
How many studs per foot of wall?
At 16 in on-center, 0.75 studs per linear foot (plus one per run) before allowances. At 24 in on-center it's 0.5 per foot; at 12 in it's 1 per foot.
What does on-center spacing mean?
The distance from the centre of one stud to the centre of the next: 16 in o.c. is the residential standard because 4×8 sheet goods (drywall, sheathing) break exactly on studs at that spacing.
Are studs for windows and doors included?
Each opening gets +2 in this count, a basic king-and-trimmer allowance. Full practice is a pair on each side (4 studs) plus a header and cripples, so add 2–4 extra studs per ordinary door or window beyond the count, more for wide openings, or raise the waste allowance to 15%.
What length studs should I buy?
For an 8 ft wall, precut 92-5/8 in studs are made for exactly that. With the three plates (1.5 in each) they land at 97-1/8 in, about 8 ft 1 in finished. For 9 ft walls, 104-5/8 in precuts. This calculator counts pieces, not lengths. Match them to your ceiling height.

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Estimate disclaimer: results are planning estimates based on standard manufacturer yields and coverage figures. Site conditions, product choice and installation method change actual quantities. Verify before you buy, and follow local building code for structural work. This tool does not replace professional engineering advice.

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