How many studs do I need?
Studs = wall length (in) ÷ spacing (in), rounded up, + 1
A 20 ft wall at 16 inches on center needs 240 ÷ 16 = 15 spaces, so 16 studs. Add 2 for each corner or wall end, about 2 for each door or window (king and jack studs), then about 10% for warped or split boards.
Studs per wall at 16 inches on center
| Wall length | Studs (no openings) |
|---|---|
| 8 ft | 7 |
| 10 ft | 9 |
| 12 ft | 10 |
| 16 ft | 13 |
| 20 ft | 16 |
16 or 24 inches on center?
16 inches is the standard for load-bearing walls and gives a stiffer surface for drywall. 24 inches uses about a third fewer studs and is common in advanced framing and non-bearing walls, where your local code allows it.
Studs per wall at 16 and 24 inches on center
| Wall length | 16 in on center | 24 in on center |
|---|---|---|
| 8 ft | 7 | 5 |
| 10 ft | 9 | 6 |
| 12 ft | 10 | 7 |
| 16 ft | 13 | 9 |
| 20 ft | 16 | 11 |
| 24 ft | 19 | 13 |
| 30 ft | 24 | 16 |
Counts are before corners, openings and waste. See standard 2x4 lengths and precut stud sizes and the 2x4 lumber guide for grades and moisture stamps.
Frequently asked questions
How many studs do I need for a 10 ft wall?
9 studs at 16 inches on center, or 6 at 24 inches, before corners and openings.
How many studs for a 12 ft wall?
10 studs at 16 inches on center, or 7 at 24 inches.
Do I need a double top plate?
Usually yes on load-bearing walls. The International Residential Code calls for a double top plate on bearing walls, with a single plate allowed only under specific framing conditions.
How many inches apart are studs in a wall?
16 inches on center is the usual spacing, and 24 inches on center is common in advanced framing and non-bearing walls. On center means from the middle of one stud to the middle of the next.
What is the actual size of a 2x4 stud?
1-1/2 by 3-1/2 inches. A precut stud for an 8 ft ceiling is 92-5/8 inches long.
Reference charts
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