Question 1

How many studs do I need for a wall?

Accepted Answer

Divide the wall length in inches by the spacing and add one to close the run. A 20-foot wall at 16 inches on centre needs 16 field studs, plus about four per opening and two per corner.

Question 2

How do I calculate studs at 16 inches on centre?

Accepted Answer

Multiply the wall length in feet by 0.75 and add one. A 20-foot wall gives 15 + 1 = 16 studs. At 24 inches on centre, multiply by 0.5 and add one.

Question 3

How many studs does a door opening add?

Accepted Answer

Four in the basic case — a king stud and a jack (trimmer) stud on each side. Add cripple studs above the header at the same spacing as the wall, and below the sill for a window.

Question 4

What is a king stud versus a jack stud?

Accepted Answer

The king stud runs full height beside the opening and is nailed to the plates. The jack, or trimmer, is shorter and sits against the king to carry the header. Both are needed: the king resists racking, the jack carries load.

Question 5

How many plates does a wall need?

Accepted Answer

One bottom plate and a doubled top plate is standard, so three times the wall length in linear feet. The doubled top plate laps at corners and intersections, which is what ties the walls together into a structure.

Question 6

Is 24-inch stud spacing acceptable?

Accepted Answer

For many non-loadbearing walls and some single-storey loadbearing conditions, yes — the IRC permits it depending on stud size, height, and load. It saves lumber and improves insulation, but drywall thinner than 5/8 inch can telegraph the framing.

Question 7

What length studs do I need for an 8-foot wall?

Accepted Answer

Pre-cut studs at 92-5/8 inches. With a 1.5-inch bottom plate and two 1.5-inch top plates, that comes to exactly 96-1/8 inches — which is why pre-cut studs exist at that odd length.

Question 8

How much do studs cost?

Accepted Answer

Standard 2×4×92-5/8 SPF studs ran roughly $3–5 each in 2025, having swung dramatically since 2020. Kiln-dried and straighter-graded stock costs more but wastes far less to crowning and culling.

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