キッチン天板にセラミックストーンは何枚必要ですか？

Calculate every countertop, island, waterfall and backsplash as a full rectangular blank, divide the total blank area by the slab area for an early estimate, then nest those blanks inside the confirmed usable slab dimensions. The cutting layout—not square metres alone—sets the final whole-slab quantity. In the Lombok Villa Kitchen Project, 7.78 m² suggested two 3200 × 1600 mm slabs, but the actual layout required three.

Calculate the Early Slab Estimate From Full Blank Sizes

Start with the finished outside dimensions of every stone component. For each rectangle, multiply length by width, convert to square metres and add the results. Include the main countertop runs, returns, island tops, waterfall ends, full-height backsplashes, upstands and any other pieces supplied from the same slabs.

Always round the result up to a whole slab, but treat that answer as a budgeting minimum—not a confirmed order quantity. It does not yet test whether the individual pieces can actually fit together on the slab.

For example, a 3200 × 1600 mm slab has a nominal area of 3.2 × 1.6 = 5.12 m². The dimension and thickness also need confirmation: a countertop thickness decision can affect fabrication, edge details and which slab specification is being priced.

Lombok Villa Kitchen Project: Island and Waterfall Layout

This client project is the Lombok Villa Kitchen Project. The kitchen includes an L-shaped worktop, a freestanding island and waterfall panels at both island ends. The selected sintered stone slab is 3200 × 1600 × 12 mm. The separate kitchen slab-size guide explains why this format was selected for the 2600 × 1000 mm island.

Step 1 — Area Alone Suggests Two Slabs

One slab contains 5.12 m² of nominal area. Dividing the kitchen's 7.78 m² by that number gives 7.78 ÷ 5.12 = 1.52. Rounding up produces an early estimate of two slabs.

That arithmetic is correct, but the conclusion is incomplete. It treats the slab as divisible area rather than a fixed rectangle that must hold five other rectangles.

Step 2 — Slab 1 Holds the Island, but Not a Waterfall Panel

The 2600 × 1000 mm island fits comfortably inside a 3200 × 1600 mm slab. It leaves a 600 × 1600 mm side strip and a 2600 × 600 mm long strip in this simplified layout. Together those remnants contain substantial area, but neither has both dimensions needed for a 1000 × 900 mm waterfall.

Step 3 — Slab 2 Holds the Main and Return Countertops

The main and return blanks are both 650 mm deep. Placing them in two horizontal rows uses 650 + 650 = 1300 mm of the slab's 1600 mm width. The 3000 mm main run and 2200 mm return therefore fit on one slab, with space still available for trim and a practical fabrication allowance subject to the fabricator's approved layout.

Step 4 — Slab 3 Holds the Two Waterfall Panels

Neither earlier slab has a remnant with the required width. A third slab therefore holds the two 1000 × 900 mm waterfall blanks. This layout leaves a large remainder that can be evaluated for other villa surfaces, but its future use does not change the three-slab order needed to produce the kitchen as drawn.

Why Sink and Cooktop Cutouts Usually Do Not Reduce the Slab Count

The main countertop in this project requires a complete 3000 × 650 mm blank before the 760 × 440 mm sink opening is cut. The return still requires a complete 2200 × 650 mm blank before the 750 × 490 mm cooktop opening is cut. Subtracting the opening areas would understate the material envelope that must fit on the slab.

A removed centre piece may sometimes become a small sample or accessory, but it cannot be counted as available beforehand to fit the countertop around it. Final opening locations also need appliance templates, clearance checks and fabrication approval.

Convert Nominal Slab Size Into Usable Cutting Space

A nominal 3200 × 1600 mm slab should not automatically be treated as a perfect production rectangle of exactly that size. The fabricator may need to square or trim the perimeter, avoid a defect, respect edge quality and add material around finished pieces for machining and polishing.

There is no responsible universal allowance to insert here. It depends on the slab, equipment, edge profile, miter detail, cut sequence and factory standard. A 3000 × 650 mm finished top may therefore be nested as a slightly larger production blank. Confirm the usable slab dimensions and every blank size with the fabricator before ordering.

The same applies to edge construction. A built-up or mitered appearance can require extra strips that are easy to miss in an area-only estimate. Coordinate the selected countertop edge profile with the cutting list.

Six Layout Decisions That Can Change the Final Quantity

Once the early estimate is known, these six decisions determine whether the blanks can share slabs safely and with the intended appearance.

Use the Third Slab Across the Villa Before Calling It Waste

In the Lombok case, the third slab is necessary for the two waterfalls but still retains a large area. The next commercial question is not “Why is so much wasted?” It is “Which approved components can fit this exact remainder?”

Possible uses include a kitchen backsplash, bathroom vanity, side table, coffee table or dining-table component. Funtek's furniture tabletop supply page shows the project information needed when slab remnants may be coordinated with furniture.

Reuse is only real when the remnant dimensions, condition, thickness, finish, vein direction and delivery schedule suit another component. The parties should also agree who owns, labels, packs, transports and stores the remainder. A useful offcut schedule records the slab batch, piece dimensions, pattern orientation and intended room.

Send This Package for Final Slab Layout Confirmation

A fabricator or slab supplier can give a much firmer answer when the enquiry includes all of the following:

The preliminary calculation can use design dimensions. Recalculate after the final site template and after the actual slab faces, seam positions and pattern direction have been approved. For projects buying complete slabs rather than installed worktops, clarify where fabrication responsibility begins and ends. Funtek's sintered stone countertop supply page outlines the project inputs used for a quotation review.

The Bottom Line

Square metres tell you whether the order is in the right general range. Only a cutting layout tells you whether every required rectangle fits. The Lombok Villa kitchen contains 7.78 m² of finished stone and therefore appears to need two 3200 × 1600 mm slabs by area, but the island and countertop layouts leave remnants that are too narrow for two 1000 × 900 mm waterfalls. The project needs three full slabs before any optional spare-slab policy is considered.