Carpentry & Trim Calculators
Framing, trim, board footage and plywood layouts. 19 free calculators.
Lumber and sheet goods are priced and sold in specific units - board feet, sheet count, linear feet of trim - that a room measurement alone doesn't give you.
These calculators convert a framing layout, a trim run, or a sheet-good project into the exact units your lumber yard sells, including standard waste for cuts and joints.
Last reviewed September 2026
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All 19 Carpentry & Trim calculators
Framing Stud Calculator
Framing stud calculator for 16 or 24 in. on-center walls: get the stud count and plate lumber length, with an allowance for corners and blocking.
Trim and Molding Calculator
Trim and molding calculator for baseboard or crown molding: get the stock pieces to buy and net length from room size, doors and waste for your project.
Board Foot Calculator
Board foot calculator for hardwood and specialty lumber: get board feet per board, the total for your order and an estimated cost from its dimensions.
Plywood Calculator
Plywood calculator for subfloors, shelving and workbenches: get the sheet count for 4x8 or 4x4 sheets with waste and an optional cost estimate.
Lumber Weight Calculator
Lumber weight calculator for dimensional lumber: get the weight per piece and total weight from nominal size, length, quantity and wood density.
Rafter Length Calculator
Rafter length calculator for a common rafter: enter run, overhang and roof pitch to get the rafter length and total rise in feet for your roof framing.
Cabinet Door Calculator
Cabinet door calculator for full overlay or inset styles: get the finished door width, height and total area from your cabinet opening size.
Wainscoting Layout Calculator
Wainscoting layout calculator for evenly spaced panels: get the panel count, actual panel width, stile count and wall area from your wall width.
Board and Batten Layout Calculator
Board and batten layout calculator for an interior accent wall: get the batten count, actual gap width, total batten length and cap rail length.
Check Square Calculator (3-4-5 Method)
Check square calculator using the 3-4-5 method: get the expected diagonal for any two leg lengths and see how far a measured corner is out of square.
Stair Stringer Calculator
Stair stringer calculator for risers, treads and stringer board length, checked against the 7.75 in. max riser and 10 in. min tread limits for your stairs.
Shed Material Calculator
Shed material calculator for a small DIY shed shell: get wall studs, wall and roof sheathing sheets and roofing squares from footprint and roof pitch.
Kitchen Cabinet Linear Feet Calculator
Kitchen cabinet linear feet calculator for a rough base and wall cabinet count, plus total linear feet to compare cabinet quotes side by side.
Countertop Slab Calculator
Countertop slab calculator for stone or quartz: get the slab count and waste-adjusted area from your countertop size and the usable area of one slab.
Metal Weight Calculator
Metal weight calculator for steel, aluminum and stainless bar, plate and tube: enter shape, dimensions and length to get the total weight and weight per foot.
Miter Angle Calculator
Miter angle calculator for baseboard, casing and chair rail: get the saw angle for each piece from any corner, including out-of-square walls.
Egress Window Size Calculator
Egress window size calculator for bedroom and basement openings: check net clear area, width, height and sill height against the IRC R310 limits.
Guardrail & Handrail Height Calculator
Guardrail and handrail height calculator: check a deck guardrail against the 36 in. IRC minimum or a stair handrail against its 34 to 38 in. range.
Crown Molding Angle Calculator
Crown molding angle calculator for compound miter and bevel saw settings. Enter your corner angle and molding spring angle to get both cut angles for your saw.