A carpenter calculator is four calculators a carpenter reaches for on the same day: the wall (studs, plates and headers), the sheathing (sheets per wall or roof), the stair (risers, treads and the stringer) and the lumber order (board feet). Each has its own page on this site with the arithmetic worked; this page is the four together, in the order a house is framed, on one worked house with a 40 by 30 footprint, 8 foot walls and a 9 foot stair. It is written for the carpenter who wants the numbers before the yard opens, and the construction cost estimator on this site prices every one of them at your own rates, with no account.
The walls: studs, plates and headers for the whole floor
The worked house has 140 feet of exterior wall and 90 feet of interior partition. At 16 inches on center the exterior run is 140 times 0.75, 105, plus one per wall segment; with four corners at three studs each and six openings adding an average of four studs, the exterior count lands near 140 studs. The partitions at 16 on center are 90 times 0.75 plus ends, about 75, plus doors. Plates are three runs of each wall's length: 420 feet of exterior plate and 270 feet of partition plate. Headers are sized to each opening's span and listed by opening. The stud calculator on this site works any single wall with its corners and openings; the totals here are those walls added up.
The sheathing: sheets for the walls and the roof
Exterior wall area is the perimeter times the height, 140 by 8, 1,120 square feet, less the openings, roughly 1,000 square feet net. A 4 by 8 sheet covers 32 square feet, so the walls take about 32 sheets before waste and 35 with the usual allowance. The roof at a 6 in 12 pitch on the 40 by 30 footprint has a plan area of 1,200 square feet and a slope factor near 1.12, about 1,340 square feet, 42 sheets before waste, 46 with it. The sheathing calculator on this site works either from the dimensions, and the panel grade the code asks for is in chapter 6 of the residential code linked below.
The stair: risers, treads and the stringer from the total rise
The 9 foot floor-to-floor stair is 108 inches of total rise. At a target riser near 7.25 inches that is 108 over 7.25, 14.9, rounded to 15 risers, and 108 over 15 is 7.2 inches per riser exactly. Fourteen treads at a 10 inch run make a total run of 140 inches, 11 feet 8 inches, which has to fit the framing opening and the landing. The stringer length is the hypotenuse of 108 and 140 inches, about 177 inches, so 2x12 stock at 16 feet with the cut list marked from the top. The stair stringer calculator on this site does the cut list; the construction standard for stairways is linked below and the residential code's egress chapter sets the rise and run limits for a dwelling.
The order: board feet, the price and what free means here
Every line above becomes lineal feet by size, and lineal feet become board feet by the piece's factor: one per foot for 2x6, two-thirds for 2x4, two for 2x12. The worked house's framing order is a few thousand board feet, and the estimator on this site prints it by size at your yard's price. Free here means the calculators run on the page with nothing stored and no account; a carpenter who wants the order kept against the job, priced once and compared to the invoice when it arrives, uses DrawScheduleWorks Pro, which keeps the estimate's lines beside the committed cost. The wood handbook linked below is the reference for species, grade and density behind every line.
Questions people ask about carpenter calculator
What does a carpenter calculator cover?
The four sums a carpenter runs on site: studs, plates and headers per wall; sheets of sheathing per wall or roof; risers, treads and the stringer per stair; and board feet per order. Each has its own worked page on this site.
Is the carpenter calculator free?
Yes. Every calculator on this site runs on the page with nothing stored and no account. Keeping the order against a job and comparing it to the invoice is what DrawScheduleWorks Pro adds.
How do I turn the framing list into a price?
Lineal feet by size become board feet by the piece's factor, and board feet times the yard's price per board foot is the line. The construction cost estimator on this site prints the lines at your own price.