REFERENCE TABLE · CONSTRUCTION · STUDS
A 12 ft wall needs 10 studs, or 80.00 linear ft. At 16 in on-center a 12 ft wall takes 10 studs of 2×4, and at 8 ft high that is 80.00 linear ft of lumber. Pick the stud size, spacing and wall height to work out the count for your wall.
A stud is sold by its nominal size, and the actual size is smaller: a 2×4 is really 1.5 × 3.5 inches. This chart lists the six stud sizes people buy most, from 2×3 to 2×12, with the actual size and the best use of each — and the lookup works out the studs and the total lumber for your wall, so the number you get is the number of studs to buy and the length to carry.
A stud is sold by its nominal size, and the actual size is smaller, because the lumber is milled down from the rough cut: a 2×4 is really 1.5 × 3.5 inches, a 2×6 is really 1.5 × 5.5 inches, and a 2×12 is really 1.5 × 11.25 inches. The studs for a wall are the wall length in inches divided by the spacing, rounded up, plus one for the end stud: studs = ceil(wall length × 12 ÷ spacing) + 1. The total lumber is the studs times the wall height, in linear feet.
At the defaults — 12 ft wall, 2×4, 16 in on-center, 8 ft high — the studs are ceil(12 × 12 ÷ 16) + 1 = ceil(9) + 1 = 10 studs, and the total lumber is 10 × 8 = 80.00 linear ft. The plus one is the end stud: without it the last bay of the wall would have no stud at its end.
| Nominal size | Actual size | Best for |
|---|---|---|
| 2×3 | 1.5 × 2.5 in | non-load-bearing partitions |
| 2×4 | 1.5 × 3.5 in | interior + exterior walls |
| 2×6 | 1.5 × 5.5 in | exterior, plumbing walls |
| 2×8 | 1.5 × 7.25 in | headers, tall walls |
| 2×10 | 1.5 × 9.25 in | headers, beams |
| 2×12 | 1.5 × 11.25 in | headers, beams |
This is a size and spacing chart, and it is explicitly not a load-bearing or span chart: it does not say how much load a stud can carry, and it does not say how far a header or beam can span. A 2×8, 2×10 or 2×12 used as a header or beam must be sized from the span tables for the load it carries, and a load-bearing wall must be checked against the building code before it is framed.
Setup: 12 ft wall, 2×4, 16 in on-center, 8 ft high.
Line 1 — the actual size. A 2×4 is 1.5 × 3.5 inches.
Line 2 — the wall length in inches. 12 × 12 = 144 inches.
Line 3 — the bays. 144 ÷ 16 = 9 bays.
Line 4 — the studs. 9 + 1 = 10 studs, counting the end stud.
Line 5 — the total lumber. 10 × 8 = 80.00 linear ft.
8 ft wall: the studs are ceil(8 × 12 ÷ 16) + 1 = ceil(6) + 1 = 7 studs, and the total lumber is 7 × 8 = 56.00 linear ft. A shorter wall needs fewer studs in direct proportion to its length, plus the same one end stud.
16 ft wall: the studs are ceil(16 × 12 ÷ 16) + 1 = ceil(12) + 1 = 13 studs, and the total lumber is 13 × 8 = 104.00 linear ft.
20 ft wall: the studs are ceil(20 × 12 ÷ 16) + 1 = ceil(15) + 1 = 16 studs, and the total lumber is 16 × 8 = 128.00 linear ft.
24 in spacing, 12 ft wall: the studs are ceil(12 × 12 ÷ 24) + 1 = ceil(6) + 1 = 7 studs, and the total lumber is 7 × 8 = 56.00 linear ft. Wider spacing saves 3 studs on this wall, which is why 24 in is the common choice for non-load-bearing partitions.
10 ft wall at 24 in: the studs are ceil(10 × 12 ÷ 24) + 1 = ceil(5) + 1 = 6 studs, and the total lumber is 6 × 8 = 48.00 linear ft.
100 ft wall: the studs are ceil(100 × 12 ÷ 16) + 1 = ceil(75) + 1 = 76 studs, and the total lumber is 76 × 8 = 608.00 linear ft. At this length the count is the length in inches divided by the spacing, plus one, with no rounding to worry about.
9 ft height, 12 ft wall: the studs stay 10, because the height does not change the count, and the total lumber is 10 × 9 = 90.00 linear ft. A taller wall needs longer studs, not more of them.
Reverse — studs to wall length: 10 studs fit a 12.00 ft wall, 7 studs fit an 8.00 ft wall, 13 studs fit a 16.00 ft wall, and 16 studs fit a 20.00 ft wall, all at 16 in on-center. Count the studs in a wall, and the length follows, because the length is the studs minus one, times the spacing, divided by 12.
The model assumes a straight wall with studs evenly spaced at 16 or 24 inches on-center, plus one end stud, and it assumes the studs are the full wall height. It assumes the nominal sizes in the table, and it leaves out the top and bottom plates, the corners, the door and window framing, and the cripple studs, which add lumber on a real wall. It does not say how much load a stud can carry or how far a header or beam can span: this is explicitly not a load-bearing or span chart. Rounding convention: studs to whole numbers, lumber to 2 decimals, and all figures are computed from unrounded values, rounded only for display.
| Output | Formula | What it means |
|---|---|---|
| Actual stud size | nominal, milled down | 1.5 × 3.5 in for a 2×4. |
| Studs needed | ceil(length × 12 ÷ spacing) + 1 | 10. |
| Total lumber | studs × wall height | 80.00 linear ft. |
| 8 ft wall | same model, 8 ft | 7 studs, 56.00 linear ft. |
| 16 ft wall | same model, 16 ft | 13 studs, 104.00 linear ft. |
| 20 ft wall | same model, 20 ft | 16 studs, 128.00 linear ft. |
| 24 in spacing, 12 ft wall | same model, 24 in | 7 studs, 56.00 linear ft. |
| 10 ft wall at 24 in | same model, 10 ft, 24 in | 6 studs, 48.00 linear ft. |
| 100 ft wall | same model, 100 ft | 76 studs, 608.00 linear ft. |
| 9 ft height, 12 ft wall | same model, 9 ft high | 10 studs, 90.00 linear ft. |
| Reverse: 10 studs | (studs − 1) × spacing ÷ 12 | 12.00 ft wall. |
| Reverse: 7 studs | (studs − 1) × spacing ÷ 12 | 8.00 ft wall. |
| Reverse: 13 studs | (studs − 1) × spacing ÷ 12 | 16.00 ft wall. |
| Reverse: 16 studs | (studs − 1) × spacing ÷ 12 | 20.00 ft wall. |
The math is exact for the numbers you enter: the studs are the wall length in inches divided by the spacing, rounded up, plus one for the end stud, and the total lumber is the studs times the wall height. What the model cannot do is measure your wall for you: measure the length and height, and check the spacing on the existing studs, because an old wall may not be on 16 in centres. It assumes a straight wall with even spacing, and it leaves out the top and bottom plates, the corners, the door and window framing, and the cripple studs. It is explicitly not a load-bearing or span chart: it does not say how much load a stud can carry, or how far a header or beam can span. For the plywood that covers the wall, see plywood size chart; for the lumber itself, see lumber size chart.
Bright Side Kit. "Stud Size Chart: Standard Studs, Spacing & Count 2026." https://brightoolbox.com/stud-size-chart/ Accessed October 25, 2026.1.5 × 3.5 inches. A 2×4 is sold by its nominal size, and the actual size is smaller because the lumber is milled down. A 2×6 is really 1.5 × 5.5 inches, and a 2×12 is really 1.5 × 11.25 inches.
10 studs at 16 in on-center. The studs are ceil(12 × 12 ÷ 16) + 1 = 10, and the total lumber is 10 × 8 = 80.00 linear ft. At 24 in spacing the same wall needs 7 studs and 56.00 linear ft.
Ceil the bays, then add one. The studs are ceil(wall length × 12 ÷ spacing) + 1: the wall length in inches divided by the spacing, rounded up, plus one for the end stud. The total lumber is the studs times the wall height.
The stud centres are 16 inches apart. On-center spacing is measured from the centre of one stud to the centre of the next. 16 in is the common choice for load-bearing and exterior walls, and 24 in is the common choice for non-load-bearing partitions.
76 studs, or 608.00 linear ft. At 16 in on-center a 100 ft wall needs ceil(100 × 12 ÷ 16) + 1 = 76 studs, and 76 × 8 = 608.00 linear ft at 8 ft high.
16 in for load-bearing and exterior walls, 24 in for partitions. A 12 ft wall at 16 in needs 10 studs and 80.00 linear ft, and at 24 in it needs 7 studs and 56.00 linear ft. Wider spacing saves lumber but holds less load and less insulation.
It does not change the count. A 12 ft wall needs 10 studs whether it is 8 ft or 9 ft high, because the count comes from the length and the spacing. The lumber changes: 10 × 8 = 80.00 linear ft at 8 ft, and 10 × 9 = 90.00 linear ft at 9 ft.
No. This is a size and spacing chart, and it is explicitly not a load-bearing or span chart. It does not say how much load a stud can carry, or how far a header or beam can span: size those from the span tables for the load they carry.