How to use it
- Enter the wall length. For a whole house, add up every wall that has the same height and stud spacing and enter the total.
- Set the height and spacing. Most houses are framed 16 in on center; 24 in is common with 2x6 walls and advanced framing.
- Count the corners and the T-intersections where other walls tie in. On a combined total, count each corner once.
- Enter how many doors and windows there are and their rough opening sizes from the plans or the maker's spec sheet.
- Check the framing details. The defaults are typical, but change them to match how your framer builds.
- Turn on sheathing if the wall gets OSB or plywood, then type prices in the cost section.
Results update as you type. Copy result gives you a plain-text lumber list, and the page address saves your numbers so you can bookmark the job.
This is a takeoff, not an engineered design
The calculator counts lumber. It does not size anything. Header depth, stud size, how a load gets down to the foundation and how the wall is braced all come from your plans, the span tables in your building code or an engineer. If a header is carrying a floor, a girder or a point load, get it sized before you buy it.
The formula
Layout studs = Wall length in inches ÷ Spacing, rounded up, + 1
Studs = Layout + Corners × Extra + T's × Extra + Openings × (Kings + Jacks)
Plate feet = Length × (1 bottom + top plates) + Window widths for sills
Header feet = (Rough opening + 2 × Bearing) × Plies, for each opening
Sheets = Wall area ÷ Sheet coverage, rounded up
Waste is added to each line before rounding up, because you can't buy part of a stud or a sheet.
Here is how openings are counted. Layout studs that fall inside a door or window are not subtracted. On the job they get cut into the short cripple studs above the header and below the sill, so you still buy them. Each opening then adds its king studs (full height, beside the opening) and jack studs (the ones the header sits on). The bottom plate runs straight through door openings and is cut out after the wall stands, so it isn't shortened. Each window also gets one flat rough sill, which is counted with the plate stock because it's usually the same lumber. If your plans call for double sills, add that footage.
A sheet taller than the wall, like a 4 × 9 on an 8 ft wall, is counted as covering 4 ft of wall length. The extra laps onto the rim joist or gets cut off.
Worked example: a 30 ft wall, 8 ft tall, 16 in on center
- The wall has 2 corners, 1 T, one door (38 in rough opening) and two windows (36 × 48 in). It has a double top plate, 16 ft plate stock, 2-ply headers and 10% waste.
- Layout: 360 in ÷ 16 = 22.5, round up to 23, plus 1 = 24 studs
- Extras: 2 corners × 2 = 4, 1 T × 2 = 2, 3 openings × 4 = 12. Total 42 studs. With 10% waste, 46.2, so 47 studs
- Plates: 30 ft bottom + 60 ft top + 6 ft of sills = 96 ft. With waste, 105.6 ÷ 16 = 6.6, so 7 pieces of 16 ft
- Headers: the door's is 38 + 3 = 41 in and each window's is 36 + 3 = 39 in. 119 in × 2 plies = 19.8 ft. With waste, buy 22 ft
- Sheathing, 4 × 8: 240 sq ft. With waste, 264 ÷ 32 = 8.25, so 9 sheets. Subtracting the openings (45.8 sq ft) brings it to 7 sheets
Common mistakes
- Counting corners twice. If you run each wall separately, give each corner to one wall only.
- Using the door size instead of the rough opening. A 36 in door needs a wider and taller hole for its frame. Use the rough opening from the maker's spec sheet.
- Forgetting the second top plate. A bearing wall usually gets a double top plate, so you buy three rows of plate, not two.
- Pricing the header as a stud. Headers are deeper lumber, or engineered beams on wide openings, and cost more per foot.
- Skipping waste. Some boards in every lift are crooked or split. Running out halfway through a wall costs more than a few extra studs.
Questions people ask
How many studs do I need per foot of wall?
At 16 in on center, the layout alone is three studs for every four feet, plus one. Corners, intersections and openings add more, so use the calculator for a real count.
What length studs do I buy for an 8 ft wall?
Precut 92-5/8 in studs are made for 8 ft walls. With a bottom plate and a double top plate, they give a wall a little over 97 in tall, which leaves room for the ceiling drywall. Check what your plans call for.
How long should a header be?
The rough opening plus the jacks it sits on. With one 1.5 in jack on each side, that's the opening plus 3 in. A 38 in door opening gets a 41 in header.
What size header do I need?
That depends on the opening width, what the wall carries and your snow and wind loads. Use the header tables in your local code or the size on your plans. This calculator only counts the footage.
Does this work for 2x6 walls?
Yes. The counts are the same; only the lumber you price changes. A 2x6 wall's header is often three plies, or two plies with insulation between them, so set the plies to match how yours are built.