Corner bead calculator

Use it free in the browser for DIY shopping lists and contractor take-offs, or call the API at $0.002 per successful request when estimating software needs the same contract.

Count outside corners and opening returns on the elevation plan

Walk every wall elevation and mark every outside corner where two drywall faces meet at an external L that will receive metal or paper corner bead from floor plate to ceiling line. Separately count every opening return edge that also takes bead—typical cases are the vertical returns at window reveals, door jamb returns finished with bead, and arched openings where a paper or vinyl bead is bent around the curve. Interior inside corners usually take paper tape rather than metal outside corner bead, so leave those off this take-off. Consistent counting across plan revisions is what keeps purchase orders honest when the architect adds a window or removes a jog that used to need bead. Send that count as outside_corners; accepted aliases include corners, outside_corner_count, corner_count, and l_corners so spreadsheet headers and form fields can reuse familiar labels. Send that count as opening_returns; aliases returns, return_count, opening_return_count, and window_returns cover common takeoff column names. Both counts are required non-negative integers: zero is valid when a straight remodel has no outside corners or no returned openings in this line item, but negative values, non-integers, empty strings, and missing fields fail with invalid_input and are not billed. Extremely large counts above the published maximum are rejected so multiplies stay stable on a Worker isolate. Do not invent corners from room perimeter alone—this endpoint does not measure plate length or on-center framing; it only multiplies the bead runs you already marked.

How wall height, return height, waste, and stick count are computed

Each outside corner is treated as a full-height bead run: outside_lf equals outside_corners multiplied by wall_height. wall_height must be a strictly positive finite number in any consistent linear unit (feet are conventional in U.S. residential work; metres work if every length uses metres). Aliases height, ceiling_height, corner_height, and H map to the same field. Each opening return uses return_height of bead: returns_lf equals opening_returns times return_height. return_height must be non-negative; when opening_returns is greater than zero it must be strictly positive so a zero-length return cannot silently hide a positive count. Aliases return_length, opening_height, return_run, and R cover schedule labels. Net linear feet is outside_lf plus returns_lf. Optional waste is a non-negative fraction of that net run, defaulting to one tenth (ten percent) for cuts, scarf joints, and damaged sticks; aliases waste_fraction, waste_factor, scrap, allowance, and overage are accepted, with a maximum of two (two hundred percent). linear_feet equals net_lf times one plus waste. Optional stick_length defaults to eight (common eight-foot metal bead sticks); aliases stock_length, piece_length, bead_length, and stick rename it. sticks is the ceiling of linear_feet divided by stick_length so you order whole sticks at the merchant. Optional precision chooses decimal places for non-integer numeric fields, defaulting to four and capped at fifteen so JSON goldens stay stable. The response echoes inputs with defaults filled, reports outside_lf, returns_lf, net_lf, waste_length, linear_feet, sticks, unit, method corners_and_returns, a formula string, a human-readable message, and step strings. Identical inputs always produce identical JSON because the path is pure arithmetic with no network, random seed, or wall clock.

API usage, pricing, drywall workflows, and practical limits

Call the free in-browser corner bead calculator for quick site estimates, lumber-yard kiosks, and contractor whiteboards without standing up a spreadsheet. POST a JSON body with outside_corners, wall_height, opening_returns, and return_height, plus optional waste, stick_length, and precision when defaults do not match your shop standard. Use the prepaid API when a renovation app, quantity-takeoff pipeline, modular home configurator, or estimating tool needs a stable contract under KIT balance at $0.002 per successful item; validation failures never consume balance after the engine rejects the request. Pair this endpoint with a drywall sheet calculator for board counts and with a corner stud calculator for framing packs so the full finish package covers boards, screws, bead, and mud. Remember that paper-faced bead, metal L-bead, bullnose, and vinyl arch bead share the same linear take-off even when the product SKU differs—select the product after you know linear_feet and sticks. Authors shipping SDKs can map linear_feet into purchase orders while showing outside_lf and returns_lf as explanatory detail for the estimator and inspector. This capability does not size joint compound bags, mesh tape, or inside-corner paper tape, and it does not auto-detect corners from a CAD drawing; you enter counts and heights that match the elevations you already measured.