Where does every stud in this wall go?
Enter one wall and its openings, get the studs, king and jack studs, cripples, headers, plates and the marks.
At a three-stud corner one wall usually carries two studs and the other one (APA, Figure 3); a two-stud corner with ladder blocking or drywall clips needs fewer.
Openings
The table gives full-height studs by span for exterior walls under 140 mph in Exposure B; the number of jack studs comes from the code's header table for your span and load. Check your local code.
Counting studs by length alone is a quick estimate; laying one wall out is a different job. You need to know which layout studs an opening swallows, how many king and jack studs it adds, and how long the cripples over the header are. This calculator does that for a single wall, and tells you where to mark the plates.
What the number means
This page does one wall at a time. The older framing calculator on this site estimates walls from their length and an opening count. Here each opening has a size and a position, so the studs it removes from the regular spacing, the king and jack studs it adds, and the cripple studs it needs above and below are counted one by one. The answer is a buying list for that wall and a list of marks to draw on the plates.
Method and variables
Studs are centered every spacing (12, 16 or 24 inches) from the left end. Each end has a group of 1, 2 or 3 studs: one stud where the wall simply ends or butts another wall, two or three at a corner or where a partition meets this wall and needs backing. Around each opening the calculator reserves a zone from the outermost king stud on one side to the outermost on the other: opening width plus the thickness of the king and jack studs on both sides. Layout studs that fall in the zone are dropped; those wholly inside the opening become cripples over the header, and under the sill for a window. The bottom plate runs under windows and is cut out under doors; the top plate is one or two layers over the whole wall. Lumber is figured from 1½ inch actual thickness of a nominal 2× board.
Worked example: a 24 foot wall with a window and a door
Wall 24 ft, studs 16 inches on center, precut studs of 92⅝ inches, two-stud groups at both ends, a 36 inch window 60 inches from the left end with the sill at 36 inches and a 36 inch door 150 inches from the left end, tops at 82 inches. One king and one jack stud per side. The layout holds 12 studs, the end groups 4, the king studs 4: 20 full-length studs. Then 4 jack studs of 82 inches, 4 cripples over the headers of 3.4 inches, 2 cripples under the sill of 34.5 inches, two 39 inch headers, a 36 inch sill, and 69.0 feet of plate (48.0 top, 21.0 bottom, the door opening cut out).
Common mistakes and limits
Measuring spacing from the stud's edge instead of its center throws every sheet joint off by ¾ inch. Counting the king studs but not the shorter jack studs is a classic short order. A wide opening needs more than one king stud: by the IRC table a 6 foot opening already needs two per side, so a 72 inch window in the same wall carries 4 king studs against 2 for a 36 inch one. Remember that this calculator gives the studs, not the structure: header sizes, the number of jack studs, bracing, hold-downs and fastening are set by the code tables for your span, load and wind. The wall is straight, the openings do not overlap, and the corner studs of the neighboring wall are counted on that wall. If an opening is too close to the end or to another opening, the page says so instead of guessing.
How do I lay out studs 16 inches on center?
Measure from one end of the wall and mark 16, 32, 48 inches and so on to the center of each stud. Because a stud is 1½ inches thick, the left edge of the second stud is at 15¼ inches (16 − ¾), the third at 31¼, and the calculator lists these edge marks for the whole wall. The first stud sits flush with the end, the last one flush with the other end, so the final space is shorter than 16 inches. Laying out from the end puts the edge of a 4 by 8 sheet of plywood or drywall on the middle of a stud.
How many studs are in a 24 foot wall?
With no openings and two studs at each end, the layout needs 17 studs between the end groups at 16 inches on center, 21 in all. One 36 inch window and one 36 inch door change that to 20 full-length studs (12 on the layout, 4 at the ends, 4 king studs), plus 4 jack studs, 6 cripples and 2 headers. At 24 inches on center the same wall needs 16 full-length studs.
What are king studs, jack studs and cripples?
A king stud runs the full height of the wall beside an opening. A jack stud, also called a trimmer, sits against it, runs from the bottom plate to the underside of the header and carries the header's load down to the floor. A cripple is a short stud above a header or below a window sill that keeps the stud spacing going. APA's advanced framing guide calls for one pair of king studs, one pair of jack studs and cripples only where they are needed to keep the spacing.
How many king studs does an opening need?
The International Residential Code ties the number of full-height studs at each end of a header to its span and to the wind exposure. In the edition printed in the Texas 2018 residential code, for less than 140 mph in Exposure B the counts are 4 ft: 1, 6 ft: 2, 8 ft: 2, 10 ft: 3, 12 ft: 3, 14 ft: 3, 16 ft: 4, 18 ft: 4; for a span in between, use the next larger span. The calculator uses that table when "by IRC table" is selected: a 36 inch opening gets 1 per side, a 6 foot opening 2, an 8 foot opening 2. Your adopted edition and local wind map decide what applies, so check your local code. The full-height stud next to the header is nailed to it with four 16d nails.
How many jack studs does a header need?
It depends on the header size and the load it carries: the IRC gives the number in the NJ column of Table R602.7(1). A single jack stud on each side is common for small openings, and a framing anchor can replace it in some cases. We did not open that table, so the calculator lets you choose 1 to 4 jack studs per side and defaults to 1. A header sized by span and load, not by habit, is also the best place to save lumber: APA notes that jack studs may not be needed with wood structural panel headers.
How long is a header?
The rough opening width plus the thickness of the jack studs on both sides: the opening plus 3 inches for one jack stud per side. For a 36 inch window that is 39 inches, as the example shows. The header's depth and plies come from the IRC span tables or an engineer. The calculator uses a depth only to work out the length of the cripple studs above it; the default is 7¼ inches, a doubled 2×8.
Can I use a single top plate?
Many walls have a double top plate, which ties the wall together and helps carry loads from above. APA's guide describes single top plates as an advanced framing option that works only when the framing above is lined up with the studs below, studs at 24 inches on center and rafters or joists over each stud. If you choose a single plate, the example's plate total drops from 69.0 feet to 45.0 feet. Ask your building department before leaving out the second plate.
Sources: APA – The Engineered Wood Association, Advanced Framing Construction Guide, Form M400 (2014); International Residential Code, R602.7.5 and Table R602.7.5 as printed in the Texas 2018 residential code (up.codes, read October 27, 2026); the IRC 2021 text of Table R602.7(1) was not opened; lumber-yard product listings for the 92⅝ inch precut stud. Check your local code. Several walls at once: wall framing calculator; door and window rough openings: rough opening calculator; the lumber for a deck: deck calculator; walls clad in boards: board and batten calculator. How we check our calculators.