How many studs a straight wall takes, from 8 ft to 40 ft long, at 16" and 24" on center. The numbers come from the stud calculator: wall length in inches ÷ spacing, rounded up, plus one stud to close the far end. A wall that divides exactly does not get an extra stud.
The plate columns count 12 ft and 16 ft boards for one bottom plate and a double top plate (3 × the wall length), with offcuts spliced into the next run. Corners, door and window openings and wall intersections are not included; add them as shown under the table.
Studs and plate boards by wall length
Studs and plate boards by wall length| Wall length | Studs, 16" o.c. | Studs, 24" o.c. | 12' plate boards | 16' plate boards |
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| 8' | 7 | 5 | 2 | 2 |
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| 10' | 9 | 6 | 3 | 2 |
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| 12' | 10 | 7 | 3 | 3 |
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| 14' | 12 | 8 | 4 | 3 |
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| 16' | 13 | 9 | 4 | 3 |
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| 18' | 15 | 10 | 5 | 4 |
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| 20' | 16 | 11 | 5 | 4 |
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| 22' | 18 | 12 | 6 | 5 |
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| 24' | 19 | 13 | 6 | 5 |
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| 26' | 21 | 14 | 7 | 5 |
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| 28' | 22 | 15 | 7 | 6 |
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| 30' | 24 | 16 | 8 | 6 |
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| 32' | 25 | 17 | 8 | 6 |
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| 34' | 27 | 18 | 9 | 7 |
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| 36' | 28 | 19 | 9 | 7 |
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| 38' | 30 | 20 | 10 | 8 |
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| 40' | 31 | 21 | 10 | 8 |
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Rounding and how to use the chart
Example: a 20 ft wall is 240". At 16" on center, 240 ÷ 16 = 15, plus the end stud = 16 studs; at 24", 240 ÷ 24 = 10, plus 1 = 11. Plates: 3 × 20 = 60 ft, which is exactly 5 boards of 12 ft, or 3.75, so 4 boards of 16 ft.
Add about 2 to 3 studs per corner, a king and a jack stud on each side of every door or window (4 more per opening) and 1 to 2 per wall intersection. Headers, sills, cripples and blocking are not counted; the stud calculator takes the extras and gives the total. Maximum spacing depends on stud size, wall height and load (IRC Table R602.3(5)).
Frequently asked questions
How many studs do I need for a 20 ft wall?
16 studs at 16" on center or 11 at 24", before corners and openings: 240" ÷ 16 = 15, plus one to close the wall. Add 4 for each door or window (king and jack studs) and 2 to 3 per corner.
How many studs for a 10 ft wall?
9 studs at 16" on center (120 ÷ 16 = 7.5, rounded up to 8, plus the end stud) or 6 at 24" (120 ÷ 24 = 5, plus 1). The plates take 30 ft of lumber: 3 boards of 12 ft.
Is it one stud per foot of wall?
As a quick rule, about one stud per foot of wall covers the layout plus corners, openings and backing on 16" centers. The layout alone is less: a 40 ft wall has 31 studs at 16" on center and 21 at 24". Count the extras for your walls, or use the calculator.
Estimates only. Check measurements, product labels and local building codes before you buy or build.