Wall Framing Calculator
Estimate studs, top and bottom plates and total lumber for a framed wall from its length, spacing and openings.
How it works
field studs = wall length(in) ÷ spacing + 1 · +3 per opening + 1 corner · plate = length × 3 (bottom + double top)
Stud count starts from the wall length in inches divided by the on-center spacing, plus one to close the last bay — a 16 in on-center wall lands a stud every 16 inches. Each opening adds framing lumber (king studs, jack/trimmer studs and cripples), estimated here at about three extra studs per door or window, and corners and ends need an extra stud. Plates run the full length three times over — one bottom plate and a doubled top plate — so plate lumber is roughly three times the wall length.
Worked example
A 24 ft wall at 16 in on center: 288 in ÷ 16 = 18, +1 = 19 field studs, +1 for the end and +6 for two openings = 26 studs. Plates = 24 × 3 = 72 linear ft, about 6 twelve-foot boards.
Frequently asked questions
What stud spacing should I use?
Sixteen inches on center is the residential standard and works with most sheet goods. Twenty-four inches on center uses less lumber and suits some engineered and energy-efficient framing, while 12 in is reserved for heavily loaded walls.
Why is plate lumber three times the wall length?
A framed wall has a single bottom plate and, in standard platform framing, a doubled top plate — two boards stacked — so the plate stock adds up to three runs of the wall length before waste.
How many studs do openings really add?
It varies with the opening width and header, but a door or window typically needs two king studs, two jack studs and several short cripples above and below. Three studs’ worth per opening is a reasonable planning allowance; a wide opening with a big header needs more.
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Estimates only — add for waste and confirm against local building codes and supplier specs.