How do I calculate how many tiles I need for a room in Sri Lanka?

Measure the room length and width in metres and multiply them for the area, subtract any openings such as a door threshold or a sunken shower, add a wastage margin for cuts (about 10%), then divide by the face area of one tile. This tool does all of that and rounds up to whole sealed boxes.

How many 600×600 tiles are in a box in Sri Lanka?

Most 600×600 mm floor tiles from Lanka Tiles and Rocell come 4 pieces to a box, which covers 1.44 m² (4 × 0.36 m²). It can differ by series, so check the number printed on the box and adjust the pieces-per-box field if it isn't 4.

How much wastage should I add when buying tiles?

Around 10% is a safe default for a typical room. Use about 5% for a large, plain, straight-lay floor with few cuts, and 15% for small bathrooms, many cut edges, or diagonal and herringbone patterns. The CIDA Building Schedule of Rates uses similar tiling allowances.

How many square metres does one box of tiles cover?

Box coverage = pieces per box × the face area of one tile. A box of 4 × 600×600 mm tiles covers 4 × 0.36 = 1.44 m². A box of 8 × 300×600 mm tiles also covers 8 × 0.18 = 1.44 m². The calculator shows box coverage for whatever size and pieces-per-box you enter.

How many 2×2 (600 mm) tiles fit in one square metre?

A 600×600 mm tile has a face area of 0.6 × 0.6 = 0.36 m², so one square metre holds 1 ÷ 0.36 ≈ 2.78 tiles. You still buy whole tiles and whole boxes, so real orders round up — this figure is only the tiles-per-m² rate.

Why does it round up to whole boxes instead of exact tiles?

Tile shops sell sealed boxes, not loose tiles, so you cannot buy the exact tile count. Rounding up to whole boxes leaves a few spare tiles, which is a feature: keep them for breakages and future repairs, because a later batch will shade slightly differently and won't match.

Can I use this for wall tiling and not just floors?

Yes. For walls, work out the wall area (wall length × height, or perimeter × height for a whole room), subtract doors and windows as openings, and enter that. The maths is identical; only the wastage tends to be higher on walls because of more cuts around fittings.

Does this include adhesive, grout, or skirting tiles?

No. This version estimates field-tile quantity and boxes only. Adhesive and grout depend on tile thickness and joint width, and skirting or border strips are ordered separately. It also does not produce an exact cut layout — it uses a wastage margin instead of a per-tile cut plan.

Sri Lanka · Home & Building

Sri Lanka Tile Calculator — how many tiles & boxes you need

Enter a room's size and the tile you're buying to get the exact tiles, sealed boxes, and rupee cost to order. It subtracts doors and openings, adds a cutting-wastage margin, and rounds up to whole boxes — so you don't make a second trip or waste money. No signup, sources cited.

By Induwara Ashinsana— Executive Director, Ryzera TechnologiesUpdated Jul 12, 2026

How many tiles & boxes?

SL tile sizes · 2026

How do you want to enter the area?

Room length × widthI know the area (m²)

Room length

Room width

Openings to subtract (doors, columns, sunken areas)

m²

A standard door is about 0.8 × 2.1 = 1.68 m². Leave 0 if none.

Tile size

Pieces per box

Wastage margin

5% for a large straight-lay floor, 10% typical, 15% for small rooms, many cuts, or diagonal patterns.

Price per box (optional)

Enter what one box costs at your tile shop to see the total order value.

Boxes to buy

= 44 tiles

Tiles needed

1 spare in full boxes

Design area

15.4 m²

Net 14 m² + wastage

Your order

Buy 11 boxes (44 tiles) of 600 × 600 mm.

Net area (after openings): 14 m²
Design area (net + wastage): 15.4 m²
Tile face area: 0.36 m² (2.78 tiles/m²)
Box coverage: 1.44 m² per box
Tiles needed (min): 43 tiles

Tiles are sold in sealed boxes, so we round up to whole boxes. Buying 1 extra tile in full boxes doubles as breakage and future-repair spares — keep them, as batches shade differently.

Sizes and pieces-per-box follow the Lanka Tiles and Rocell catalogues (SLS 1122 nominal sizes); the wastage default follows the CIDA Building Schedule of Rates. Cross-checked 2026-07-12. Full sources are listed below the calculator.

How it works

The calculator turns a room measurement into an order you can hand to a tile shop. Every length is worked in metres and every tile size in millimetres, converted to metres before any area maths. There are five steps.

Net area. In dimensions mode the gross area is length × width; in area mode you type the total directly. The openings you enter (doors, columns, sunken shower trays) are subtracted to give the net tiling area.
Design area (with wastage). design = net × (1 + wastage/100). The default 10% follows the tiling allowances in the CIDA Building Schedule of Rates — roughly 5% for a large, straight-lay floor, rising to 10–15% for small rooms, many cut edges, or diagonal patterns. Areas are held to two decimal places (cm² precision), the way a quantity surveyor quotes them.
Tile face area. (L/1000) × (W/1000) m². A 600×600 mm tile is 0.6 × 0.6 = 0.36 m², so one square metre holds 1 ÷ 0.36 ≈ 2.78 tiles.
Tiles needed. ceil(design ÷ tile face area). This is the minimum whole tiles that cover the design area.
Boxes to buy. Box coverage is pieces per box × tile face area, and boxes = ceil(design ÷ box coverage). Because tiles are sold only in sealed boxes, the count always rounds up; the tiles those boxes contain (boxes × pieces per box) is shown so you see the small surplus that doubles as breakage spares.

The box count is cross-checked a second way. Buying enough boxes to hold every needed tile is ceil(tiles ÷ pieces per box), and for a whole-number pieces-per-box that is provably the same figure as rounding the design area over box coverage — so both routes agree to the box. Tile sizes and pieces-per-box defaults come from the Lanka Tiles and Rocell catalogues (SLS 1122 nominal sizes); pieces-per-box is editable because it varies slightly by brand and range, so always confirm the number printed on the box.

Worked examples

Living-room floor · 600×600 mm

4.0 m × 3.5 m, no openings, 10% wastage, Rs 4,200 per box

Gross area: 4.0 × 3.5 = 14.00 m² (no openings → net 14.00 m²)
Design area: 14.00 × 1.10 = 15.40 m²
Tile face: 0.6 × 0.6 = 0.36 m² (2.78 tiles/m²)
Tiles needed: ceil(15.40 ÷ 0.36) = ceil(42.78) = 43 tiles
Box coverage: 4 × 0.36 = 1.44 m² → boxes: ceil(15.40 ÷ 1.44) = 11
Order: 11 boxes = 44 tiles → 11 × Rs 4,200 = Rs 46,200

Bathroom walls · 300×600 mm (with a door)

2.0 m × 2.0 m room, 2.4 m high, one door, 12% wastage, Rs 3,600 per box

Wall area: perimeter 8.0 m × height 2.4 m = 19.20 m²
Subtract door 0.8 × 2.1 = 1.68 m² → net = 17.52 m²
Design area: 17.52 × 1.12 = 19.62 m²
Tile face: 0.3 × 0.6 = 0.18 m² (5.56 tiles/m²)
Tiles needed: ceil(19.62 ÷ 0.18) = 109 tiles
Box coverage: 8 × 0.18 = 1.44 m² → boxes: ceil(19.62 ÷ 1.44) = 14
Order: 14 boxes = 112 tiles → 14 × Rs 3,600 = Rs 50,400

Exact fit · 600×600 mm (edge case)

14.40 m² area entered directly, 0% wastage — a perfect whole-tile fit

Design area: 14.40 m² (0% wastage)
Tiles needed: 14.40 ÷ 0.36 = 40.0 exactly → 40 tiles
Boxes: 14.40 ÷ 1.44 = 10.0 exactly → 10 boxes
The tool's tolerance stops floating-point noise (14.40 ÷ 0.36 stored as 40.0000000001) from wrongly bumping this to 41 tiles or 11 boxes.

Frequently asked questions

Sources & references

Tile sizes, pieces-per-box defaults, and the wastage convention were last cross-checked against these sources on 2026-07-12. Pieces-per-box and prices vary by brand, range, and shop, so confirm both at the point of purchase.

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