How to frame a wall: stud layout, plates, rough openings, and headers

Platform framing is a three-step sequence: snap your layout lines, build the wall flat on the floor, then stand it up. Every step is faster when the math is done before the first nail goes in. That means knowing your stud count, your rough opening sizes, and your header before you pull lumber.

Stud count — the formula

Base studs = floor(wall length ÷ spacing) + 1

Then add:
  +3 per corner         (2 corner studs + 1 drywall nailer)
  +2 per T-intersection (partition wall tie-in nailer)
  +2 per opening        (king studs, full-height either side)
  +2 per opening        (jack studs, bear the header)
  +varies               (cripples above header + below sill)

Example — 24 ft exterior wall, 16" oc, one 36" door opening:
  Base:    floor(24 × 12 / 16) + 1  = 18 + 1 = 19 studs
  2 corners:                         +6
  1 door (king + jack each side):    +4
  ─────────────────────────────────────────
  Total studs:                        29

  (Cripples above the door header = number of stud bays
   above the header to the double top plate, calculated
   separately once you know the header height.)

Spacing choices and what they mean structurally

• 16″ on center — the residential standard for exterior load-bearing walls. Handles standard roof and floor loads with 2×4 or 2×6 studs. This is what your inspector expects to see unless you specify otherwise.
• 24″ on center — acceptable for interior non-load-bearing partition walls and, in some code situations, exterior walls with advanced framing (OVE). At 24″ oc the rafter or joist above must span farther between bearing points, so it needs to be a larger size than at 16″ oc. Don’t mix spacings without rechecking the span tables above.
• 12″ on center — used for extra-heavy loads, shear walls specified by an engineer, or stud walls supporting concentrated point loads. Rarely required by code alone; usually called out on engineered drawings.

Plate material

Every platform-framed wall uses three plates: a single bottom plate (pressure-treated where it contacts concrete), and a double top plate. The double top plate is what transfers loads from the roof and floor above down into the studs — it also ties corners and intersections together.

Plate linear feet = wall length × 3
  (bottom plate × 1 + top plate × 2)

Add 10% for laps and waste.

Corner laps: the upper top plate must lap the lower top plate
by at least 4 ft at every corner and T-intersection.
The lap is what locks the walls together — skip it and the
corner can rack apart.

Rough opening sizes

The rough opening (RO) is the framed hole before the door or window unit goes in. It is larger than the nominal door or window size to allow room for the jamb, shimming, and flashing.

Door RO:
  Width  = door width + 2"   (1" jamb each side)
  Height = door height + 2½"  (jamb + threshold clearance)

  Standard 3068 door (3'-0" × 6'-8"):
  RO = 38" wide × 82½" tall

Window RO:
  Width  = window width + ½"  (¼" shim each side)
  Height = window height + ½"

  Manufacturers publish their own RO specs — use those
  instead of a generic formula. Andersen, Pella, and Marvin
  all differ slightly.

Common mistake: sizing the RO to the finished opening
(the interior trim reveal). That's 2"–3" narrower than
you need. Always size to the rough opening spec.

Header sizing

The header is the beam that spans the rough opening and carries the load of the roof, floor, or wall above. The wider the opening and the heavier the load above it, the bigger the header must be.

Opening width    Header (load-bearing exterior, single story)
──────────────────────────────────────────────────────────
Under 3 ft       Doubled 2×4  (non-LB) / doubled 2×6  (LB)
3 to 5 ft        Doubled 2×8
5 to 8 ft        Doubled 2×10
8 to 10 ft       Doubled 2×12
10 to 12 ft      Doubled 2×12 (verify with engineer)
Over 12 ft       LVL — requires span table + engineer sign-off

For 16 ft garage door openings: LVL is the standard call.
"You're going to want to go with an LVL."

2×6 wall note: the doubled header (3" total) is narrower than
the 5½" wall. Fill the gap with a plywood spacer (½" OSB)
sandwiched between the two header pieces.

Reduce one size for interior non-load-bearing partitions,
or for a top-floor wall with only a shallow attic above.
Verify with IRC Table R602.7 and your local AHJ.

Jack studs and king studs

Every rough opening uses four structural members alongside it, two on each side:

• King stud — a full-height stud that runs from the bottom plate to the top plate. It flanks the opening on each side and receives the header end nails. King studs are always full height regardless of opening size.
• Jack stud (trimmer) — a shorter stud that sits inside the king stud and bears directly under the header end. The jack stud sets the rough opening height. “You will always have at least one jack stud for any opening.” Wider openings (typically over 5 ft) get double jack studs.

Load path through a wall opening

Understanding the load path helps you understand why every member at an opening is sized and placed the way it is.

Roof load (live + dead)
  → down rafters
  → into double top plate
  → through cripple studs above the header
  → into the header (spanning the opening)
  → down the jack studs
  → into the sill plate
  → into the foundation footings

The header is a beam. The jack studs are its columns.
Remove a jack stud and the header sags — or worse, the
load punches through the sill plate.

Tall wall safety

A framed wall is light and manageable at 8 ft. At 10 ft it starts to get unwieldy. At 12 ft or more it is a serious lift. “Short walls are easy to lift, and tall walls are much harder to lift.” Practical rules:

• Have enough crew. A 20 ft wall needs at least four people — two to push from the bottom, two to control the top and set the brace the moment it clears vertical.
• Pre-cut and pre-nail wall jacks (or rent them). Trying to control a tall wall going vertical with no jacks is how people get hurt.
• For walls over 10 ft or walls with significant glass (heavy headers), a telehandler or crane is worth the rental cost.
• Brace immediately. Once the wall is plumb, nail the diagonal braces to stakes in the slab before anyone lets go.

Platform framing vs. balloon framing

Virtually all residential construction built after the mid-20th century is platform framed. Balloon framing is rare today but you will encounter it in older homes.

• Platform framing — each floor is a separate horizontal platform. Studs run from floor to ceiling only (typically 8–10 ft), then a new platform is built on top. Standard lumber lengths work. Easiest to frame, easiest to stand up.
• Balloon framing — studs run the full height of two stories (16–20 ft), with the floor joists notched into a let-in ribbon board mid-height. Requires long lumber (costly and hard to source), taller walls are dangerous to stand, and fire can travel inside the wall cavity from foundation to attic without firestopping. Used almost exclusively in remodel situations on existing balloon-framed buildings.

Lumber grade and species

Stud-grade lumber is stamped for the purpose. In practice:

• Number 2 is the grade you’ll see on 95% of framing lumber. It’s the workhorse — meets all residential code requirements for studs, plates, and most headers.
• SPF (Spruce-Pine-Fir) — light, straight, common in the Midwest and West. Good for studs and plates. Shorter allowable spans than SYP for joists.
• SYP (Southern Yellow Pine) — denser and stronger, preferred in the South. The go-to for structural joists, headers, and beams where spans matter. Heavier than SPF.
• Actual dimensions: a 2×4 is 1½″ × 3½″. A 2×6 is 1½″ × 5½″. Nominal sizes are what you order; actual sizes are what you measure. This matters for rough opening math and for plywood spacers in 2×6 headers.

Common mistakes

• Not squaring the layout before nailing. Snap the wall lines on the slab, pull diagonals, and confirm they match before any stud goes in.
• Confusing rough opening with finished opening. The RO is larger — it includes room for the jamb and shimming. Sizing the RO to the finished opening is one of the most common framing errors on DIY builds.
• Forgetting the double top plate. A single top plate does not transfer loads correctly at corners and intersections and will fail inspection.
• Missing the stud count at corners and T-intersections. These require extra studs for load transfer and drywall backing — they're not in the base formula.
• Not lapping the upper top plate by 4 ft minimum at corners. The lap is structural — it ties the walls together so the corner doesn't rack.
• Skipping jack studs or using a single jack where a double is required. The header has nowhere to bear and will eventually crack the drywall above or worse.

Related

• What size header for a window or door opening
• How to estimate framing lumber
• How to calculate rafter length
• BuilderCalc — construction calculators for iOS and Android

Note: Header sizes and stud spacing requirements are governed by IRC R602 and local amendments. Engineering is required for headers over 12 ft, any opening with a point load above, and high-wind or seismic zones. Verify with your building department before framing.