Trade & construction Australia
Tile Calculator Australia
Tiling is the job where ordering short is worst: the next batch rarely matches the first. This calculator counts the tiles from the area and tile size, adds an allowance for cuts and breakage, and converts the total to boxes.
Free, no signup Runs in your browser
Length × width, minus any areas you will not tile.
Tiles to order
—Tiles for the area
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Allowance
—
Boxes to order
—
Tile area including joints
—
Estimated tile cost
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The working
How many tiles do I need?
Divide the area by the area one tile covers including its grout line, then add an allowance for cuts: 10% for a straight layout, more for diagonal or patterned layouts. A 12 m² floor with 600 × 600 mm tiles and 3 mm grout needs about 33 tiles, or 37 with a 10% allowance.
Measuring
Measure the length and width of each area to be tiled and multiply, then add them up. Deduct fixed items such as a bath hob, but not small gaps. For walls, measure from the floor or tray to the height you will tile and take off windows and doors.
Use the tile size on the box, not the nominal size: many tiles are slightly smaller or rectified to a different size.
Boxes and batches
Tiles are sold in boxes with a fixed number of tiles or area. Entering tiles per box lets the calculator round up to full boxes. Always buy from a single batch, since shade and size can vary between production runs, and keep spare tiles for future repairs.
For outdoor paving, use the paver calculator.
How this is calculated
The rule, step by step, so you can check any figure by hand.
area of one tile with grout = (width + joint) × (length + joint)tiles for the area = area ÷ area of one tiletiles to order = tiles for the area × (1 + allowance), rounded upboxes = tiles to order ÷ tiles per box, rounded up
The allowance is for offcuts and breakage, and it rises with layout complexity. A straight layout wastes little because most cuts at one wall can be reused at the opposite wall, while diagonal and herringbone layouts create more offcuts that cannot be reused. Small rooms and rooms with many obstacles need more.
Tile size changes the count dramatically: halving a tile's width and length quadruples the number of tiles. Large-format tiles use fewer pieces but need a flatter floor and more careful setting out.
A worked example
A 12 m² floor tiled with 600 × 600 mm tiles, 3 mm grout, laid straight.
- Tile with grout line603 × 603 mm
- Tiles for the area33.0
- With 10% allowance37
About 37 tiles.
Buy all the tiles for the job from the same batch and keep a box spare.
Grout and adhesive
Grout width depends on the tile and whether it is rectified. Narrower joints suit rectified tiles, and wider ones hide variation in unrectified tiles. Adhesive and grout quantities depend on tile size and trowel notch, so check the product data sheet.
What it leaves out
Trims, waterproofing, adhesive, grout and the cost of laying are not included. Wet areas need waterproofing to the National Construction Code, which a licensed waterproofer should provide.
What this calculator does not do
- Rectangular areas; add areas separately
- Allowance is a rule of thumb
- Adhesive and grout are not calculated
- Wet-area waterproofing must be done by a licensed person
Common questions
How many tiles do I need for 10 m²?
About 28 tiles at 600 × 600 mm, or 31 with a 10% allowance.
How much extra tile should I buy?
10% for straight layouts and 15% to 20% for diagonal or patterned layouts.
Do I include the grout in the tile size?
Yes. The calculator adds the joint to each dimension.
Can I use leftover tiles later?
If they are from the same batch. Keep a box for repairs.
How do I tile around fixed items?
Deduct their area from the total, then rely on the allowance for the cuts.
Where these numbers come from
- National Construction Code (ABCB) The code that sets minimum building requirements in Australia
- Your Home — Australian Government guide to sustainable homes Independent guidance on insulation, materials and design
Method last reviewed 2026-10-28 This calculator uses fixed rules rather than rates that change, and its method is re-checked against the sources above at least once a year. Out of date? Tell us and we will fix it.
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