How to calculate marble and tile quantity and cost

What you need

• A studio account with Smart Planning switched on (it is in preview, and sign-up opens soon).
• A computer or a tablet: phones show the estimate but can’t lay floors.
• The rooms drawn in Smart Planning.
• A price for each material. The app has no built-in material prices: it uses the price you type for the plan, your studio’s own price, or the shop’s price in Materials.

Steps in the app

1. Open the plan and pick the Floors & Walls tab.
2. Pick a material on the left (filters: Marble, Granite, Tiles, Wood, Stone), or make a Custom material with its price per sq ft, sq m or piece.
3. Choose Floor above the plan and click the room. A new floor is laid straight (wood staggered) with a 4 in skirting of the same material, except in bathrooms and other wet rooms; marble is diamond polished.
4. In the Room panel, change the Pattern (Straight, Diagonal 45°, Staggered, Herringbone), the piece size (Laid in), Border, Centre inlay, Skirting, Diamond polishing or Labour if you need to.
5. For wall tiles, choose Walls and click the walls; set Dado and cladding to 2 ft, 4 ft, 7 ft or Full.
6. Open the Estimate tab: the total, the price per sq ft, and Where to buy with each material in sq ft and in slabs, boxes or pieces. If a line says Add a price, type its price there. Press Excel to download it.

How the calculation works

Quantity = laid area × (1 + wastage %). The laid area is measured inside the walls; the skirting adds its running length × its height.

Wastage: marble and granite 10%, quartz and terrazzo 8%, porcelain/vitrified and ceramic tiles 5%, wood 7%, stone cladding 10%, others 7%. Diagonal and herringbone add 5%, big pieces in a small room add up to 10% more, borders 5%, inlays 10% and skirting 5%.

Slabs, boxes and pieces are rounded up to whole ones in the list; the cost uses the exact quantity.

Labour and bedding use the laid area without wastage. Default rates: floor laying ₹25 per sq ft, dado laying ₹30, diamond polishing ₹25, skirting ₹15 per running ft.

Stone floors go on a 1.5 in sand-cement bed at 1:4: the bed’s volume × 1.33 is the dry volume, shared between cement (50 kg bags of about 1.23 cu ft) and reeta sand, plus 0.4 kg of cement slurry per sq ft. Tiles go on adhesive: one bag per 40 sq ft. Grout: 1 kg per 50 sq ft of 2 × 2 ft tiles (more for smaller ones). Wood needs no bedding.

Worked example

Marble: a 20 × 15 ft living room (300 sq ft inside the walls, no door drawn yet, so the 4 in skirting runs all round: 70 running ft), laid straight and polished, marble at ₹150 per sq ft.

Tiles: a 12 × 10 ft bedroom (120 sq ft, 44 running ft of skirting) in 600 × 600 mm vitrified tiles, boxes of 15.5 sq ft at ₹700 a box, laid straight on tile adhesive.

Example prices: marble at ₹150 per sq ft and tiles at ₹700 a box are for this example only; every other rate is the app’s default (October 2026). Use your own. Each line is worked out to the paisa and rounded at the end.

Common mistakes

• Ordering the laid area only: add the wastage, and more for diagonal or herringbone.
• Forgetting the skirting: in the marble example it adds 23.3 sq ft of marble.
• Expecting the cost of whole boxes: the list rounds up to 10 boxes, but the cost uses the exact 9.2 boxes.
• Leaving a material without a price: its line says Add a price and the total leaves it out.
• Forgetting sand and cement: for a marble floor they are a real part of the cost.

Questions

• See the feature: Floors and Walls

More guides

• How to calculate false ceiling cost
• How to draw a house floor plan online
• How to make a 3D walkthrough of a house plan
• How to design a house front elevation
• How to make a GST invoice for architecture fees