Tile Quantity Calculation: Tiles, Boxes, Wastage, Skirting, Adhesive and Grout

Divide the floor area by the area of one tile and you have the fewest tiles the job can possibly take. Count the tiles along each wall, round each count up and multiply, and you have the most it could take. The right order sits between those two numbers, and this guide shows how to find it for your own room, then adds the boxes, the skirting, the mortar bed or adhesive and the grout.

The measuring rules come from IS 1200 (Part 11), the Indian Standard for measuring floor finishes, dado and skirting. The bed comes from IS 1443, the code for laying floor tiles, and tile sizes from IS 15622. One bedroom floor is worked through to the last bag at the end.

There are no rupee figures here. Tile and grout prices change by brand, town and month. The quantities do not.

What is the formula for tile quantity?

The basic tile quantity calculation is one line:

Number of tiles = floor area ÷ area of one tile

A 600 × 600 mm tile covers 0.6 × 0.6 = 0.36 m². A floor of 8.91 m² therefore needs 8.91 ÷ 0.36 = 24.75, which you round up to 25 tiles. That is the minimum, and it only holds if every cut piece is used somewhere else on the floor.

Two details make the answer more exact. First, tiles are laid with a joint between them. IS 15622 calls the tile plus its joint the co-ordinating size, and its modular tiles are sized to leave a nominal joint of 2 to 5 mm (1.5 to 5 mm for the most porous group, which is mostly wall tiles). So a 600 mm tile with a 3 mm joint takes up 603 mm of floor. That matters when you count rows. It barely moves the area answer.

Second, the sizes buyers use in feet are rounded. A “2 × 2” tile is really 600 × 600 mm, and 600 mm is 23.6 inches, not 24.

Take a 1,000 sq ft floor. Counted as “4 sq ft a tile” it needs 250 tiles of 600 × 600 mm. Counted at the real 3.88 sq ft it needs 259. Those nine missing tiles are the ones you go back to the shop for, and they may not match the shade of the first lot.

How do you measure the floor area for tiling?

Measure from wall to wall on the bare brickwork. IS 1200 (Part 11), as amended in 1989, says length and breadth are measured before the skirting, dado or wall plaster goes on. This fits the way tiles are laid: IS 1443 clause 10.4 asks for the floor tiles at the wall to run about 10 mm under the plaster, skirting or dado.

The other measuring rules in the same part of IS 1200:

• Lengths are taken to the nearest 0.01 m and areas to the nearest 0.01 m² (clause 2.4).
• Floor tiling and dado are measured in square metres. Skirting is measured in running metres, with its height stated (clause 4.12).
• No deduction is made for a void of 0.2 m² or less, such as a pillar base or a floor trap (clause 4.3).
• A strip of tiling 30 cm wide or less that does not match the main floor, such as a border band, is measured in running metres (clause 2.7.1).
• Square cutting at joints and edges, and the waste it creates, is part of the rate. Cutting for a diagonal pattern is measured on its own (clauses 2.6 and 4.4).

Those rules decide what a contractor is paid for. They are not the same as what you order. A floor trap under 0.2 m² is still paid as tiled area, but you will not lay a tile over it. For ordering, count the tiles the way the next section shows. How these units sit in a bill of quantities is set out in the construction estimate format guide.

How many extra tiles do you need for cutting and wastage?

The usual site shortcut is to add a flat 5 or 10 per cent to the area count. It works for small tiles in a big room. It fails for big tiles in a small room, because the waste depends on where the last row of tiles has to be cut.

The rule that settles it is about half a tile. A cut piece narrower than half a tile can be cut in pairs, two from one tile. A cut piece wider than half a tile uses a whole tile, and the offcut is usually too small to use.

So a careful count goes in three steps:

1. Full tiles: divide each wall length by the tile size plus joint, keep the whole number, and multiply the two.
2. Cut pieces: along each wall, check the leftover width. Under half a tile, divide the number of pieces by two and round up. Over half, take one tile per piece.
3. Corner: one more piece where the two cut rows meet, unless a spare half is left over from step 2.

Here is what that does to the same 3.3 m × 2.7 m room (about 10.8 × 8.9 ft, or 96 sq ft) with four common tile sizes:

Read the last column against the first. With 300 mm tiles the careful count equals the area count, so a flat 10 per cent would buy ten tiles you do not need. With 800 mm tiles the real waste is two tiles on fourteen, about 14 per cent, so a flat 5 per cent leaves you short.

The 800 mm row also shows a layout problem. An 88 mm strip along one wall looks poor and chips easily. Masons often shift the whole layout to split that cut between both walls, or start from the centre of the room. That changes the cut sizes, so do the count on the layout you will actually lay. Diagonal laying cuts every tile at the walls and wastes far more, which is why IS 1200 measures its edge cutting as a separate item.

How many tiles are in a box?

It depends on the maker and the size, so read it off the carton or the maker’s catalogue, which print both the pieces per box and the area per box. Then:

Boxes = tiles needed ÷ pieces per box, rounded up

If a carton of 600 × 600 mm tiles holds 4 pieces, it covers 4 × 0.36 = 1.44 m² (15.5 sq ft). Twenty-five tiles is 6.25 boxes, so you buy 7 and have 3 spare.

Keep those spares. IS 15622 clause 6.1 requires each tile or its packing to carry a batch number or date of manufacture, because colour and size drift a little from one firing to the next. Buy every box from one batch, check the number on each carton before the truck leaves, and store the spare tiles for repairs. A broken tile in five years is easy to replace from your own store and hard to match from a shop.

How do you calculate skirting tiles?

Skirting is the low band of tile along the foot of the wall. Work it in running metres, as IS 1200 does:

Skirting length = room perimeter − door widths

Most sites cut skirting from the same floor tile. A 600 mm tile cut into 100 mm strips gives six strips on paper. Plan on five, since the saw cut and a chipped edge often cost one. At five strips of 0.6 m, each tile gives 3 m of skirting.

For the 3.3 m × 2.7 m room with one 0.9 m door: perimeter 2 × (3.3 + 2.7) = 12.0 m, less the door, is 11.1 m. That needs 11.1 ÷ 0.6 = 18.5, so 19 strips, which is 4 tiles. IS 1443 clause 14.1 has skirting fixed only after the floor is laid, and clause 14.2 fixes it directly on 1:4 cement mortar with no separate backing coat.

How do you calculate wall tiles for a bathroom or kitchen?

Wall tiling up to a set height is called dado and is measured in square metres. For ordering, work each wall on its own, because each wall has its own cut column at the corner and its own cut row at the top.

For each wall: tiles across = wall length ÷ (tile width + joint), rounded up by the half-tile rule; rows up = dado height ÷ (tile height + joint), the same way. Subtract the tiles a door or window would take only when the opening is a whole tile or more. Small openings such as a pipe or a switch box are cut around and still use the tile.

IS 1443 clause 14.2 sets a backing of about 10 mm of 1:4 cement mortar on the wall for dado, and clause 14.1 says the wall area to be tiled is left unplastered. That is one more reason to agree the dado height before plastering starts: the plaster quantity calculation for those walls stops where the tiles begin. A bathroom wall that will take tiles also needs its waterproofing coat first, as the waterproofing chemicals guide sets out room by room.

How much cement and sand for the tile bed?

The traditional way to lay floor tiles in India is on a bed of cement mortar. IS 1443 clause 9.1.1 specifies one part cement to six parts coarse sand by volume, and clause 9.1.2 keeps the bed between 10 mm and 30 mm thick at any point. The tiles are then pressed into a thin neat cement slurry spread over the bed. Contracts often call for a 20 mm bed, and some ask for a richer 1:4 mix.

The arithmetic is the same as for plaster: bed thickness × area × 1.27 for the dry volume, split by the mix, at 1,440 kg per m³ of cement. The building material calculation guide explains where those two numbers come from.

The cement slurry under each tile is extra and is not in the table. IS 1443 does not give a quantity for it, so ask your contractor how much his rate allows and count it as its own line. Watch the bed thickness on site. An uneven slab that needs 30 mm in places uses half as much cement again as a 20 mm bed.

On a large floor the bed mortar is often mixed by machine. For that, compare concrete mixer models and their drum sizes.

How much tile adhesive is needed per sqm?

Tile adhesive is a polymer-modified cement powder that holds a tile on a bed only a few millimetres thick. It replaces the thick mortar bed where the slab is already level, and vitrified tiles, which absorb very little water, grip it far better than plain mortar. The Indian Standard for adhesives is IS 15477, and the guide to construction chemicals places them alongside the other products a house uses.

How much you need depends on the bed thickness, which the notched trowel sets. One maker’s figure gives the scale. MYK LATICRETE’s data sheet for its LATICRETE 303 adhesive gives about 55 to 60 sq ft per 20 kg bag, laid with a 6 mm × 6 mm square-notched trowel for a 3 mm bed. That works out to about 3.6 to 3.9 kg per m², or 18 to 20 bags of 20 kg per 100 m².

The same sheet says coverage changes with the notch size, the tile type and size, and how flat the floor is. A bigger tile needs a bigger notch, and a large slab tile is often buttered on the back as well, so it takes more. Use the figure on the data sheet of the adhesive you are actually buying, at the trowel size it names.

How much grout is needed per sqm?

Grout is the paste that fills the joints between tiles. Its quantity is pure geometry: the volume of the joints, times the density of the grout.

Grout (kg per m²) = (L + W) ÷ (L × W) × joint width × joint depth × density

L and W are the tile length and width in mm, the joint width and depth are in mm (depth is usually the tile thickness), and density is in kg per litre. The first part is the length of joint per square metre of floor, which is why small tiles take far more grout than big ones.

Grout makers publish the same arithmetic. ARDEX ENDURA’s product page for its epoxy grout gives a mixed density of 1.70 and a coverage table, and the formula reproduces that table: for 600 × 600 × 10 mm tiles with 3 mm joints the page lists 5.88 m² per kg, which is 0.17 kg per m². The table below is worked at 1.70:

Cement-based grouts are heavier. The same maker lists its cement polymer grout at a wet density of 1.80, so multiply the table by about 1.06 for those. Joint width matters more than anything else here: going from 2 mm to 5 mm joints multiplies the grout by two and a half.

Worked example: one bedroom floor, start to finish

The room is 3.3 m × 2.7 m (about 96 sq ft), with one 0.9 m door. The floor takes 600 × 600 × 10 mm vitrified tiles with 3 mm joints and a 100 mm tile skirting. The carton says 4 pieces a box.

Two numbers in that table are worth checking with your mason before you buy. The first is the layout: if he plans to start from the centre of the room, the cut sizes change and so may the count. The second is the bed: a 20 mm mortar bed on a slab that is out of level by 10 mm somewhere is really a 30 mm bed in that corner.

Where tiling sits in the house estimate

Tiling comes after the plaster and before the paint. The house construction cost calculator shows how the flooring line sits next to the rest of the budget, and the same quantity method is used for steel in the bar bending schedule. For the cement you will turn this into bags of, check the current cement price on the day you order, and see cement bag weight and size for what a bag holds.

The floor slab under those tiles is concrete, cast long before the tiler arrives. If you are planning that work, compare live concrete mixer models and prices and connect with a dealer. More estimating guides sit under construction cost.

Prices, specifications and features are indicative, vary by variant, location and date, and should always be confirmed with the official OEM or authorised dealer before any purchase decision. DesiMachines is not liable for decisions taken on the basis of information that may have changed after publication.

Code references: IS 1200 (Part 11) : 1977 (method of measurement, paving, floor finishes, dado and skirting) with Amendment No. 1 (1989), clauses 2.4, 2.6, 2.7.1, 4.3, 4.4 and 4.12; IS 1443 : 1972 (laying and finishing of cement concrete flooring tiles), clauses 9.1.1, 9.1.2, 10.4, 14.1 and 14.2; IS 15622 : 2006 (pressed ceramic tiles), clause 4 and Tables 1, 3 and 7 (co-ordinating size and joint width) and clause 6.1 (marking). Adhesive coverage from the MYK LATICRETE technical data sheet for LATICRETE 303 (rev. 01/25); grout density and coverage table from the ARDEX ENDURA epoxy grout and cement polymer grout product pages, read October 2026. Mortar quantities use a dry volume factor of 1.27 and 1,440 kg per m³ of cement. The worked example is an illustration; your drawing, the tile carton and your contract decide the real figures.