Tile Calculator
Number of tiles and boxes for any area.
Area to tile
Measure in metres, or type in a total you already know.
“Less” is an optional deduction in m² for a window, vanity or shower base you won't tile.
3 mm is a common joint; rectified large-format tiles are often laid at about 2 mm. Wall tiles are often about 6–9 mm thick, outdoor pavers about 20 mm.
Leave waste blank to use 10% for a straight (grid) lay. Straight and brick lays are usually 10%; diagonal and herringbone about 15%.
Tiles needed
11 tiles (3 boxes)
3.42 m² at 2.75 tiles per m² plus 10% waste. Buying 3 × 4 = 12 tiles leaves 1 spare.
Straight (grid) lay
Preview is illustrative only. Tile 600 × 600 mm, 3 mm joint.
Materials & cost
| Item | Quantity | Cost |
|---|---|---|
| Tiles | 3 boxes · 12 tiles · 4.32 m² | — |
| Adhesive | 1 × 20 kg | — |
| Grout | 1 × 5 kg | — |
| Waterproofing | 3.42 m² | — |
| Labour | 3.42 m² | — |
Open “Pricing” and enter your own prices to see a cost estimate.
Grout: about 0.144 kg/m² for your tile size, thickness and joint, plus 10% extra.
| Tile size | Tiles per m² | Tiles for this job |
|---|---|---|
| 300 × 300 mm | 10.89 | 41 |
| 450 × 450 mm | 4.87 | 19 |
| 600 × 600 mm | 2.75 | 11 |
| 300 × 600 mm | 5.47 | 21 |
| 600 × 1200 mm | 1.38 | 6 |
| 75 × 300 mm (subway) | 42.31 | 160 |
| 100 × 100 mm | 94.26 | 355 |
| 200 × 200 mm | 24.27 | 92 |
At your 3 mm joint and 10% waste.
How to Use the Tile Calculator
Measure each floor and wall you plan to tile in metres, pick a tile size and layout, and this tile calculator works out how many tiles you need, how many boxes to buy, and how much adhesive and grout the job will take. Add your own prices if you want a tiling cost estimate too. Whether you think of it as a tile estimator, a tiles calculator or a square metre calculator for tiles, the maths is the same: get the area right, count tiles per square metre including the grout joint, then allow for waste.
Tiling a timber, laminate or hybrid floor instead? Use the flooring calculator.
Tile Calculator Formulas
Tiles needed = area × tiles per m² × (1 + waste %), rounded up
Boxes = tiles needed ÷ tiles per box, rounded up
Grout (kg per m²) = ((length + width) ÷ (length × width)) × thickness × joint × 1.6, all in mm
Grout is approximate (1.6 is a typical density factor in kg/dm³), and the calculator adds 10% extra. An adhesive coverage of about 4 m² per 20 kg bag is typical with a 10 mm notched trowel for medium and large tiles; always check the bag.
Worked Example: a Bathroom Floor
A bathroom floor measures 2.4 m × 1.8 m (4.32 m²) with a 0.9 m² shower base that won't be tiled, leaving 3.42 m² (about 36.8 sq ft). The tiles are 600 × 600 mm, 9 mm thick, with a 3 mm joint and a straight lay with the default 10% waste.
Tiles per m² = 1 ÷ (0.603 × 0.603) = 2.7502, so the floor needs 3.42 × 2.7502 = 9.41 tiles before waste. With 10% extra, that rounds up to 11 tiles. At 4 tiles (1.44 m²) per box you would buy 3 boxes, which is 12 tiles (4.32 m²) and leaves 1 spare tile. Adhesive at 4 m² per bag comes to 1 bag. Grout uses about 0.144 kg/m², or 0.54 kg including 10% extra, which is 1 bag of 5 kg.
Measuring and Wastage by Layout
Measure each floor and wall as a rectangle, and split L-shaped rooms into two. For walls, use the length of the wall and the height you will tile to. Deduct windows, doors, a vanity or a shower base only if they will not be tiled behind or under. Wastage covers cuts at the edges, breakage and mistakes: straight (grid) and brick (offset) lays are commonly allowed about 10%, and diagonal and herringbone lays about 15% because more tiles are cut at the walls. Awkward rooms, patterned or directional tiles and very large formats can justify more.
Large-Format Tiles and Grout Joints
Large-format tiles such as 600 × 1200 mm cover more area per tile, so you need fewer of them, but they can waste more at the edges of small rooms and they are heavier and less forgiving to lay. Lippage, where one tile edge sits higher than its neighbour, is more noticeable with large tiles, so a flat substrate, the right adhesive and trowel, and often a levelling system are used to keep the surface even. Rectified tiles have precisely cut edges and are commonly laid with narrow joints of about 2 mm; other tiles are often laid with 3 mm or more. A wider joint uses more grout and slightly reduces the tiles per square metre, and the joint should match what the tile supplier recommends.
What Goes Into a Tiling Cost
The tiling cost calculator adds up the items most jobs include. Tiles are charged on the whole boxes you buy, not just the area you tile, so leftovers are part of the cost. Adhesive and grout are charged per bag. Waterproofing applies to wet areas such as bathrooms, laundries and showers, and is installed under the tiles; in Australia it must comply with AS 3740 and local regulations, and in some states it must be done by a licensed or qualified person. Labour is usually quoted per square metre or as a fixed price. Because rates differ by region, tile size, layout and site conditions, this page asks for your own prices rather than guessing. Items it does not include, such as removal of old flooring, floor preparation and levelling, trims, sealer, and delivery, are worth asking your supplier or installer about.
Frequently Asked Questions
- How many tiles do I need?
- Measure the area in square metres, multiply by the number of tiles per square metre for your tile size and grout joint, then add an allowance for cuts and breakage. A 600 × 600 mm tile with a 3 mm joint works out to about 2.75 tiles per m², so a 20 m² room needs roughly 55 tiles before waste and about 61 with 10% extra. Enter your measurements above and the tile calculator does this for you and rounds up to whole tiles and boxes.
- How do I use a square metre calculator for tiles?
- Multiply length by width in metres to get the area in m², then subtract anything you won't tile, such as a shower base or window. For several rooms or walls, add each surface as its own row and the calculator totals them. If you already know the area, switch to “Enter total m²” and type it in.
- How much extra should I allow for wastage?
- Straight and brick (offset) lays commonly use about 10%, while diagonal and herringbone layouts need more cuts, so around 15% is typical. Rooms with lots of corners, pillars or cut-outs, and very large or very small tiles, can need more. You can override the percentage from 0% to 50%, and it is sensible to keep a few spare tiles for future repairs.
- What is a tile estimator or tile estimator calculator actually working out?
- It converts an area into a shopping list: the number of tiles, how many boxes to buy, bags of adhesive and grout, and, if you add your own prices, a total cost. The key step is that tiles cover slightly less than their face area because the grout joint takes up space, so the calculator includes the joint when counting tiles per square metre.
- How do I work out a tiling cost in Australia?
- A tiling cost is the sum of several parts: the tiles (priced per m² or per box, and charged on the whole boxes you buy), adhesive, grout, waterproofing for wet areas, labour, and sometimes extras like trims, levelling, removal of old flooring and delivery. This tiling cost calculator lets you enter each price from your own quotes and shows the total and the cost per square metre. Labour rates vary by region, job complexity and tile size, so get written quotes rather than relying on a generic figure.
- How do I estimate a bathroom tiling cost?
- A bathroom usually has a floor and several walls, so add each as a separate surface and deduct windows, the vanity footprint and the shower base if you won't tile them. Include waterproofing in the pricing section, because wet areas need a waterproofing membrane applied before tiling. In Australia, domestic wet-area waterproofing is covered by AS 3740 and local regulations, and in some states it must be done by a licensed or qualified person, so confirm the requirements with your installer or local authority.
- Can I use this as a flooring calculator for tile?
- Yes. Choose your tile size and layout, enter the floor area, and the results include tiles, boxes, adhesive and grout. For timber, laminate, hybrid, vinyl or carpet, use the flooring calculator instead, which is set up for boxes, underlay and skirting rather than tiles and grout.
- How do I use the tile calculator in square feet?
- Enter your measurements in metres and the calculator shows the area to be tiled in both square metres and square feet (1 m² = 10.7639 sq ft). If you only have feet, divide by 3.281 to convert each length to metres, or divide an area in sq ft by 10.7639 and use the total m² option. Tiles in Australia are sold in millimetre sizes and boxes are quoted in m², so it helps to keep the order in metric.
- How many boxes of tiles should I buy, and why buy extra from the same batch?
- Divide the tiles needed (including waste) by the tiles in a box and round up. Tiles are made in production batches that can differ slightly in shade and size, so buy everything for the job at once from the same batch and keep a spare box or a few loose tiles in case of future repairs. Check the batch or shade number printed on each box before you open them.