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.
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.