How Many Tiles Do I Need? Working Out Quantities and Wastage
31 August 2026 · Tile Touch
The short answer: measure the area you are tiling in square metres, then add extra for cuts, breakages and future repairs. Most straightforward wall and floor jobs work out at your measured area plus about 10 percent wastage. Below is how to get there, step by step, and how to handle the trickier cases like mosaics and patterned layouts.
The quick method
Tiles in Australia are usually sold by the square metre (m2), so your goal is to work out your total area in m2 and buy a little more than that.
- Measure the width and height (or length) of each surface in metres.
- Multiply width by height to get the area of each surface.
- Add all the surfaces together for your total m2.
- Add a wastage percentage on top (see below).
Example: a wall 3 metres wide and 2.4 metres high is 3 x 2.4 = 7.2 m2. Add 10 percent and you order about 7.9 m2.
How much wastage should I add?
Wastage covers the offcuts you cannot reuse, the odd tile that chips during cutting, and a few spares to keep aside. As a general guide:
- Standard straight (stack or grid) layout: add around 10 percent.
- Diagonal or brick-bond layouts: add around 15 percent, because angled cuts create more waste.
- Patterned or directional tiles, or lots of small cuts around fittings: lean towards 15 percent or more.
- Large rooms with few obstacles: you may get away closer to 10 percent.
Keep any leftover tiles after the job. If a tile cracks in a few years, a matching spare from the same batch saves you hunting for a replacement that may no longer be stocked.
Don't subtract doors and windows (mostly)
It is tempting to deduct the area of a window or a door opening, but for small openings it is safer to tile the full wall area in your calculation. The cuts around an opening produce waste anyway. Only deduct large fixed features, such as a full shower screen wall or a big cabinet run, and even then keep your wastage margin.
Working out mosaic quantities
Mosaics are made up of small pieces held on a backing sheet, and they are still sold and calculated by the square metre. So the method is the same: work out your area in m2, add wastage, and order that many square metres of sheets.
Mosaics do need a slightly more generous margin. Sheets are trimmed to fit corners and edges, and you often cut through the backing between pieces, which can leave awkward offcuts. For finger and kit kat styles like the Gracemere Bone White Speckle Gloss Concave Kit Kat Finger Mosaic Tile, or fishscale shapes such as the Wellwood Water Green Gloss Fishscale Mosaic and Wellwood Black Gloss Fishscale Mosaic, the interlocking edges mean it pays to round up.
Hexagon and penny round mosaics follow the same rule. Ranges like the Lucas Mini White Gloss Hexagon Mosaic, the Lucas Large Black Matt Hexagon Mosaic and the Vogue Gold Matt Penny Round Mosaic curve around edges nicely, but the rounded pieces still create trimming waste, so 15 percent is a sensible starting point.
A worked feature-wall example
Say you are doing a splashback behind a kitchen bench: 2.6 metres long and 0.6 metres high. That is 2.6 x 0.6 = 1.56 m2. For a square mosaic such as the Anzac Gloss Ocean Blue Square Mosaic or the Fairway Small Plain White Gloss Square Mosaic 48x48mm, add 15 percent for the cuts around the power points and the ends: 1.56 x 1.15 = about 1.8 m2. Round up to the nearest full sheet or box when you order.
Buy it all in one go
Order your whole quantity, including wastage, at the same time. Tiles are made in batches, and colour or finish can vary slightly from one production run to the next. This matters most with gloss and hand-finished looks. Ordering everything together means it comes from the same batch, so your wall or floor stays consistent.
Order a sample first
Screens do not show colour, gloss level or texture accurately. Before you commit to a full quantity, order a sample so you can see the tile in your own light. Tile Touch offers samples and ships Australia-wide, and you are welcome to see the ranges in person at our Waterloo showroom in Sydney.
Quick checklist before you order
- Measured every surface and added them up in m2.
- Chosen a wastage percentage that suits your layout (10 to 15 percent, more for complex jobs).
- Ordered the full amount in one batch.
- Set aside spares for future repairs.
- Checked a sample first.
Frequently asked questions
How do I convert my measurements to square metres?
Measure each surface in metres, then multiply width by height for each one and add them together. For example, 1500 mm is 1.5 metres, so a surface 1.5 by 2 metres is 3 m2. Always measure in metres rather than millimetres to keep the maths simple.
Is 10 percent wastage always enough?
For a simple straight layout on a plain wall or floor, 10 percent is usually fine. Step up to about 15 percent for diagonal patterns, brick-bond layouts, mosaics, or rooms with lots of cuts around fittings. When in doubt, round up rather than down.
Should I include spare tiles in my order?
Yes. Keeping a few spare tiles from the same batch means you can replace a cracked tile later with an exact match. Your wastage margin often leaves you with these spares, so store them somewhere safe once the job is done.
Do mosaics use more tiles than regular tiles?
Mosaics are calculated the same way, by the square metre, but they generally need a slightly higher wastage allowance because of the trimming involved. For finger, fishscale, hexagon and penny round styles, plan for around 15 percent to cover the cuts.
Can I get help working out my quantity?
Yes. Send through your measurements and the tile you are looking at, and we can help you check your m2 and wastage. You can also order samples online or visit the Waterloo showroom to see the tiles before you buy.