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Wall Framing Calculator: How Many Studs Do I Need?
Count studs, plates and sheathing for a framed wall at 16 or 24 inches on center, including extra studs for corners, wall intersections and door and window openings.
How many studs in a wall?
Start with the studs on layout: divide the wall length in inches by the spacing and add one for the end.
studs = wall length (in) ÷ spacing, rounded up, + 1
Then add extras: about 2 per corner and 2 per wall intersection (for nailing backing), and about 3 per door or window opening for the king studs, jack studs and cripples that are not on the regular layout. Finally, add 10% because some studs will be twisted, bowed or split.
Worked example
A 20 ft wall at 16 in on center: 240 ÷ 16 = 15, plus 1 = 16 studs. Two openings add 6, for 22, and 10% extra makes 25 studs. Plates are one bottom plate and a double top plate, so 3 × 20 = 60 ft, which is four 16 ft boards. Sheathing the outside takes 6 sheets of 4 × 8 OSB or plywood. At $4.50 a stud, $10 a plate board and $18 a sheet, the materials come to about $260.
Precut stud lengths
| Ceiling height | Precut stud | Why |
|---|---|---|
| 8 ft | 92⅝ in | + three 1½ in plates = 97⅛ in, room for ½ in drywall on the ceiling and an 8 ft wall sheet |
| 9 ft | 104⅝ in | Same logic for a 9 ft wall |
| 10 ft | 116⅝ in | Same logic for a 10 ft wall |
16 or 24 inches on center?
- 16 in is standard for bearing walls and gives a stiffer wall for hanging cabinets and shelves.
- 24 in (advanced framing) uses about a third fewer studs and leaves more room for insulation, but needs single-stud openings, aligned framing and thicker drywall in some cases. Check local code for load-bearing walls.
Headers over openings are sized from the span and the load above, and are not included here. For finishing the wall, see the drywall calculator and insulation calculator.
Frequently asked questions
How many studs do I need for a 20 ft wall?
At 16 in on center a 20 ft wall needs 16 studs on layout. Add about 3 per door or window and 2 per corner, then 10% for culls: about 25 studs with two openings.
How many studs per linear foot of wall?
A quick rule is one stud per linear foot at 16 in on center, which covers the layout plus typical extras. At 24 in on center use about 0.75 per foot.
What length studs do I need for an 8 ft wall?
Use 92⅝ in precut studs. With a bottom plate and double top plate they make a 97⅛ in wall, which leaves room for the ceiling drywall and a full 8 ft sheet on the wall.