Stud Calculator
Calculate framing lumber for a stud wall: studs at 16 or 24 inch centers with corner and opening allowances, plus top and bottom plates — the standard shopping list for any framed wall.
+2 studs each
+4 studs each (kings + jacks)
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Enter a price per stud to estimate cost.
You might also need:Drywall Calculator·Board Foot Calculator
Stud wall math
total = (field + corners × 2 + openings × 4) × waste
plates = wall length × 3 (bottom + doubled top)
A 20-foot load-bearing wall at 16-inch centers: 16 field studs, plus 4 for two corners and 4 for a door opening — 27 studs with 10% waste, and 60 linear feet of plate stock (four 16-foot 2×4s). Headers over openings are extra and depend on span.
Studs per wall length (16″ o.c., field only)
| Wall length | 16″ o.c. | 24″ o.c. |
|---|---|---|
| 8 ft | 7 | 5 |
| 12 ft | 10 | 7 |
| 16 ft | 13 | 9 |
| 20 ft | 16 | 11 |
| 40 ft | 31 | 21 |
Framing tips
- Layout from one end: hook the tape on the wall end and mark 15¼″ then every 16″ — the X goes on the same side of the line every time, and drywall edges land on stud centers.
- Crown up, cull hard: sight every stud; bowed ones become blocking, twisted ones go back.
- Precuts save time: 92⅝″ studs exist so you don't cut 2×4s all day.
- Sheathing the wall? Count sheets with the drywall calculator; total the lumber order in board feet.
Frequently asked questions
How many studs do I need per foot of wall?+
At 16-inch centers, figure one stud per foot of wall as a rule of thumb — the extra beyond the strict count covers corners, openings and blocking. A 20-foot wall means about 20 studs. At 24-inch centers it drops to roughly 0.75 per foot.
Should studs be 16 or 24 inches on center?+
16 inches is the standard for load-bearing walls and anything getting drywall; it gives a stiffer wall and aligns with 48-inch sheet goods. 24-inch spacing is acceptable for non-load-bearing partitions and saves about 25% of the lumber.
What length studs do I buy for 8-foot walls?+
Buy 92⅝-inch "precut" studs. With a bottom plate and doubled top plate (4½ inches of plate total), they produce a wall that finishes at standard 8-foot ceiling height after drywall. For 9-foot ceilings, use 104⅝-inch precuts.
How many plates does a stud wall need?+
One bottom plate and two top plates (doubled) is standard for load-bearing walls, so total plate lumber is 3 × the wall length. Non-load-bearing partitions can use a single top plate where code allows.
How many extra studs should I buy?+
Add 10–15%: corners need extra studs (2–3 each), door and window openings need king and jack studs, and every lumber pile includes a few bowed or twisted culls you will reject on sight.