Calculator + chartEnter your measurements below and it works the answer out.
Field studs = ceil(wall length in inches ÷ spacing) + 1. The spaces are rounded up so the last one is short rather than over, and a stud closes each end. Corners and openings are added on top.
| Wall length | 16 in centers | 24 in centers | 12 in centers |
|---|---|---|---|
| 8 ft | 7 | 5 | 9 |
| 10 ft | 9 | 6 | 11 |
| 12 ft | 10 | 7 | 13 |
| 16 ft | 13 | 9 | 17 |
| 20 ft | 16 | 11 | 21 |
| 24 ft | 19 | 13 | 25 |
| 30 ft | 24 | 16 | 31 |
| 40 ft | 31 | 21 | 41 |
Field studs only — the run of the wall, with a stud closing each end. Spaces are rounded up, so a 10 ft wall at 16 in centers is 8 spaces (the last one 8 in) and 9 studs. Corners and openings are extra, and the calculator adds them.
The count. Wall length in inches divided by the spacing gives the number of bays; add one to close the far end. A 20 ft wall is 240 inches, which is 15 bays at 16 in centers, so 16 studs in the field.
Why 16 inches. Sheet goods come in 4 ft widths, and 16 divides into 48 exactly three times, so every sheet edge lands on a stud. 24 in centers works for the same reason with two bays per sheet, and 12 in centers with four.
Corners take three. A standard framed corner uses three studs: two forming the corner itself and one turned to give the drywall on the inside face something to land on. Advanced framing gets it down to two with drywall clips, at the cost of a detail the drywaller has to know about.
Openings take four before anything else. Two king studs running full height and two jack studs carrying the header, one each side. The header itself, the cripples above it and the sill below a window are extra and depend on the span — this calculator counts the studs, not the structure.
Plates. Three times the wall length in linear feet: a single bottom plate and a doubled top plate. Buy in lengths that let you stagger the joints in the double top plate rather than stacking them.
What this does not count. Headers, cripples, blocking, bracing and fire stops all depend on the span and the load. Those come from a plan or an inspector, and no calculator should pretend otherwise.
16 in the field at 16 inch centers: 240 inches divided by 16 is 15 bays, plus one to close the end. Add three per corner and four per door or window on top of that.
Wall length in inches ÷ spacing, then add one. At 16 in centers a 12 ft wall is 144 ÷ 16 = 9, plus one, so 10 field studs.
Because sheet goods are 4 ft wide and 16 goes into 48 exactly three times, so every sheet edge lands on a stud. It is a spacing chosen to suit the sheets, not the timber.
For many non-load-bearing and some load-bearing walls, yes, and it saves timber. It needs 5/8 in drywall on ceilings to avoid sag, and whether it is permitted for a bearing wall depends on the load and the code where you are.
92 5/8 inches for an 8 ft wall and 104 5/8 for a 9 ft wall. The precut length plus a single bottom plate and a doubled top plate comes to the finished height, which is why the number looks odd on its own.
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