Stud Calculator

Divide the wall length in inches by the stud spacing, round up, add one for the closing end, then add extra studs for every corner and every door or window opening; plates are three times the wall length.

The Formula

Layout studs = ⌈wall length (in) ÷ spacing (in)⌉ + 1. The rounding up covers the last partial bay, and the +1 is the stud that closes the far end of the wall. On top of that layout count, framers add extras where the wall needs more than a single stud. A corner or a T-intersection with another wall usually takes about two additional studs so both walls have solid nailing for drywall. Each rough opening gets a king stud and a jack (trimmer) stud on each side, which adds roughly four studs. The layout studs that land inside the opening aren't subtracted, because they get cut down into cripples above the header and below a window sill. Both extras are editable so you can match your own framing style. Plates are counted in linear feet: one bottom plate plus a doubled top plate is 3 × wall length. That total is divided by your board length and rounded up. The waste percentage is applied to both studs and plates before rounding up.

Example: A 20 ft Wall at 16 in OC

A 20 ft wall is 240 inches. 240 ÷ 16 = 15, so the layout needs 15 + 1 = 16 studs. With 2 corners at 2 extra studs each (4) and 3 openings at 4 extra studs each (12), the total is 16 + 4 + 12 = 32 studs. Adding 10% waste gives 35.2, which rounds up to 36 studs. For plates, 3 × 20 = 60 linear feet, or 66 ft with waste, which is 5.5 twelve-foot boards, so buy 6 boards.

Frequently Asked Questions

Does this work for 2x6 walls too? Yes. The count depends only on length, spacing, and openings, not on the stud's depth, so the same numbers apply to 2x4, 2x6, or metal studs framed on the same layout.

Should I use 16 or 24 inches on center? 16 in OC is the common default for load-bearing and interior walls. 24 in OC is allowed in many situations under current residential codes and saves lumber, but check your local code and your sheathing and drywall requirements first.

What about wide openings? Openings wider than about 5–6 ft often need doubled jack studs under the header. Raise the "extra studs per opening" value for those, or enter wide openings as two.

Limitations

This is a material estimate for a straight run of wall, not a framing plan. It doesn't count headers, sills, blocking, fire blocking, or the cripple studs cut from short offcuts, and it assumes precut studs already match your wall height. Structural requirements such as stud size, spacing for bearing walls, and header spans come from your local building code.