How many tiles, bags and litres does your Wagga bathroom actually need?
A standard Wagga main bathroom tiled floor to ceiling comes to about 26 square metres of surface, which becomes roughly 29 square metres ordered once you add 10 per cent wastage: about 20 boxes of 300x600 porcelain, 7 bags of adhesive, around 5 kg of grout and about 17 litres of waterproofing membrane. Materials alone run $1,500 to $3,100. Size the job with the estimator below, then add one spare box and keep it in the shed.
Size your job, then see what the materials cost.
This works out quantities first: total tiled area, how much to order with wastage, boxes, tiles, adhesive, grout and membrane. The dollar figure at the bottom is the materials supply cost only, which is what you would spend at a tile shop. It is not the job price. For the installed cost of the whole room see the Wagga cost guide and our 2026 pricing.
How to measure it properly with a tape and a phone.
Twenty minutes with a tape gets you a number you can order against. The trick is to measure surfaces, not rooms.
- Draw the room on paper first, roughly to shape. Four walls, mark the door, the window, the shower, the bath and the vanity. You will refer back to this constantly and it stops you double counting a corner.
- Measure the floor. Length times width. If the room is L-shaped, split it into two rectangles and add them. Subtract the footprint of anything that sits on the slab and is not being moved: a built-in bath is typically 1.5 x 0.75 metres, so that is 1.13 m² off the total.
- Measure each wall separately. Width times height, wall by wall, written on your sketch. Do not measure the perimeter and multiply, because the four walls in a bathroom are almost never the same height once you account for a bulkhead over the shower.
- Subtract the openings. A standard internal door is 0.82 x 2.04 metres, so 1.67 m². A typical bathroom window is 0.9 x 0.6, so 0.54 m². Subtract the band of wall hidden behind a bath, usually 1.5 metres long by 0.5 metres high.
- Do not subtract small things. Leave the mirror, the towel rail, the toilet and the vanity in. You tile behind and around them, and the offcuts from those areas are not reusable anyway.
- Add the extras people forget. The shower niche has a base, two sides, a top and a back, which is 0.5 to 0.9 m² on its own. A hob has a top and two faces. A window reveal adds three narrow strips. A stepped bulkhead adds a return.
- Photograph the sketch and every wall. Take the photo square on from about 2 metres back, with the tape held against the wall so the scale is in shot. Send those with your enquiry and we can sanity check your numbers before you order anything.
One practical note for older Wagga houses. Rooms in the 1950s and 1960s stock around Turvey Park and Ashmont are frequently 15 to 25mm out of square across a bathroom, and a room that is out of square eats more tile than the arithmetic suggests, because the cut row down one side tapers. If a diagonal measurement across the floor differs from the other diagonal by more than about 10mm, use the higher wastage figure.
Not sure your numbers are right?
Send your sketch and wall photos with an enquiry. We will check the quantities before you order a pallet of tile you cannot return.
Wastage, adhesive, grout and membrane: the allowances that matter.
Wastage
Wastage is not carelessness, it is geometry. Every perimeter tile gets cut and the offcut is usually the wrong shape for anywhere else. Use 10 per cent for a straight or stack bond in a simple rectangular room, 12 per cent for 600x600 and above, and 15 to 18 per cent for herringbone, chevron or a 45 degree diagonal, where nearly every edge tile is a cut and the offcut is a triangle. Add another 5 per cent for a room with a hobless shower, a stepped niche or more than four internal corners. Then round up to whole boxes, because tile is sold by the box: at 1.44 m² per box, 28.7 m² means 20 boxes, not 19.9.
Adhesive
Coverage is set by the notch size the tile demands, not by preference. A 20 kg bag of a cement-based adhesive covers roughly 4.5 m² at a 10mm notch for 300x600, about 3.3 m² at a 12mm notch for 600x600, around 3.5 m² for a 200x1200 plank, and as little as 2.3 m² for 600x1200 that has to be back-buttered to reach the coverage the standard asks for in a wet area. Mosaic sheets on a 6mm notch go a long way, about 6 m². Buy one bag more than the arithmetic says, because running out mid-wall with half a bay set is a bad afternoon.
Grout
Almost everybody overbuys grout by a factor of three. The consumption depends on the joint width, the tile thickness and the tile size, and it is genuinely small for large tiles. As a guide, and including practical wastage from sponging and part bags: mosaics take about 1.9 kg per square metre, 100x300 subway about 0.45, 300x600 about 0.2, 600x600 about 0.14 and 600x1200 about 0.11. A 26 m² bathroom in 300x600 therefore needs about 5 kg, which means one 5 kg bag is cutting it fine rather than generous. Buy 10 kg, use what you use, and keep the sealed remainder for the repair you will eventually want.
Waterproofing membrane
A two-coat liquid membrane uses roughly 1.2 to 1.5 litres per square metre across both coats. The area is not just the shower: it is the whole bathroom floor, the shower walls to about 1800mm, and a 150mm band up the remaining walls, plus the reinforcing tape and the bond breakers at every junction. For a typical Wagga bathroom that comes to about 15 to 18 litres, so a 15 litre pail with a top-up, or a 20 litre pail. This is the one material where buying short causes real damage, because the second coat gets stretched thin to make the pail last and a thin membrane is the single most common reason a shower fails inside a decade. Note that in NSW the membrane has to be applied by a licensed waterproofer regardless of who buys it: see the waterproofing rules for Wagga.
The other small things
Allow one 300ml cartridge of colour-matched neutral cure silicone per 8 to 10 linear metres of internal corner, which is usually 2 to 3 cartridges for a bathroom. Allow aluminium or PVC edge trim for every exposed tile edge, sold in 2.5 metre lengths. Allow one bag of levelling clips and wedges per 10 m² if you are laying anything 600mm or larger. And allow a tub of penetrating sealer if you have chosen a natural stone or an unglazed porcelain, which is one more reason most Wagga bathrooms end up in glazed porcelain instead.
Under-ordering, and why it costs more here than in Sydney.
Tiles are fired in batches and the shade varies between them. Every box carries a batch or calibre code, and a supplier will match it while they have that batch on the floor and not afterwards. When you run 2 boxes short at the end of a wall, three things happen at once. The replacement boxes may be a different batch and visibly different in daylight, which on a feature wall is the difference between a good room and a room you notice every morning. Nobody owes you a remedy for it, because the variation is disclosed on the box. And the top-up has to be found.
That last part is what makes it worse in the Riverina than in a capital city. A shade-matched top-up frequently has to come from a Sydney or Melbourne warehouse on general freight, which is 1 to 3 weeks, and in the meantime a half-tiled bathroom sits with a crew that has moved to another job and cannot simply come back the following morning. The insurance against all of that is two extra boxes at $90 to $240. It is the cheapest risk reduction available on the entire job, and the leftover box is also what lets us replace a cracked tile in year seven without hunting a discontinued line.
The second most expensive sizing error is the opposite one: over-ordering a tile you cannot return. Most Wagga and Albury suppliers will take back full, unopened, undamaged boxes of a stocked line within a set period, often with a restocking fee of around 15 to 25 per cent, and will take back nothing at all on a special order or an indent line. Ask about the returns policy before you pay, in writing, and keep the boxes dry and unopened until they are needed.
A real Wagga bathroom, with the numbers added up.
A three bedroom brick veneer in Bourkelands, built in the mid 1990s. Main bathroom 2.4 by 2.6 metres, 2.4 metre ceilings, a built-in bath along the long wall, one standard door, one small window. Tiling floor to ceiling in a 300x600 glazed porcelain, straight lay.
| Line | Working | Result |
|---|---|---|
| Room floor | 2.4 x 2.6 | 6.24 m² |
| Less bath footprint | 1.5 x 0.75 | minus 1.13 m² |
| Floor to tile | 6.24 less 1.13 | 5.1 m² |
| Gross wall area | perimeter 10.0 x height 2.4 | 24.0 m² |
| Less door | 0.82 x 2.04 | minus 1.67 m² |
| Less window | 0.9 x 0.6 | minus 0.54 m² |
| Less wall behind bath | 1.5 x 0.5 | minus 0.75 m² |
| Walls to tile | 24.0 less 2.96 | 21.0 m² |
| Total tiled surface | 5.1 plus 21.0 | 26.1 m² |
| Wastage, straight lay | 26.1 x 1.10 | 28.7 m² to order |
| Boxes at 1.44 m² | 28.7 divided by 1.44, rounded up | 20 boxes, 28.8 m² |
| Spare box kept back | plus 1 | 21 boxes, 168 tiles |
| Adhesive at 4.5 m² per bag | 27.4 divided by 4.5, rounded up | 7 x 20 kg bags |
| Grout at 0.2 kg per m² | 26.1 x 0.2 | 5.2 kg, so buy 10 kg |
| Membrane, two coats | floor plus shower walls, at 1.4 L per m² | about 17 litres |
| Materials supply total | tile, adhesive, grout, membrane kit, trims and silicone | $1,500 to $3,100 |
Materials only, indicative Wagga Wagga 2026. The installed price for the same room, including strip-out, prep, licensed waterproofing and labour, sits in the $4,500 to $9,500 range on our pricing page.
When you should not be buying your own tiles at all.
Plenty of clients supply their own tiles and it works out fine, particularly when they have fallen for a feature tile and want exactly that one. But there are four situations where doing the ordering yourself reliably costs more than it saves.
- You are buying at full retail. The trade price on a stocked field tile is often below the shelf price by enough to wipe out the saving you thought you were making. Ask us to quote supply and lay as well, then compare the two side by side. We are happy either way and we will show you both numbers.
- The tile is a special order or an indent. If it cannot be topped up and cannot be returned, the risk of getting the quantity wrong sits entirely with you, and the consequence is a stalled job rather than a phone call.
- You have not chosen the adhesive yet. The tile decides the adhesive. A large format porcelain in a wet area needs a flexible cement-based adhesive of the right class, and the wrong bag from a hardware aisle is the most common cause of drummy tiles we get called to. If you buy tile and adhesive separately without checking, that mismatch is not covered by anybody.
- You are tiling outdoors or around a pool. The slip rating, the frost tolerance and the thickness all matter more than the look, and Wagga gets both a genuine frost and 40 degree surface temperatures. Read the specification guide before you buy anything for an outdoor area.
And the other honest note: if you are only replacing a few cracked tiles or dealing with tired grout, none of this applies. That is a repair or a regrout, and the quantity you need is one box or one bag. We would rather tell you that than sell you a pallet.
Have us check your quantities before you order
Send your measurements or just photos of each wall with a tape in shot, and we will confirm the square metres, the boxes and the wastage within 1 business day, free.
Quantity questions we get asked.
How many square metres of tile does a standard Wagga bathroom need?
How much wastage should I add to a tile order?
How many bags of adhesive and how much grout will I need?
What is the sizing mistake that costs the most money here?
Do I measure the room or the surfaces I am tiling?
How much waterproofing membrane does a bathroom take?
Next: what happens on site day by day, the cheapest sensible way to do the job, who covers what if it fails, and floor tiling across Wagga Wagga and the Riverina, including Kooringal and Bourkelands.
Get the quantities and the installed price in one quote
Free on-site measure. We take the measurements off your actual walls, allow the right wastage, and give you a fixed written price.