Tiling: tiles, adhesive, grout and backer board
Tiles are counted from the area divided by one tile plus its joint, with extra for cuts and breakages. 10 m² of 300 x 300 mm tiles is 120 tiles with 10% extra, about 50 kg of adhesive (3 bags of 20 kg) with a 10 mm notched trowel, and 3.8 kg of grout at a 3 mm joint.
Below is everything we have on tiling in the UK: tiles, adhesive and grout, backer board, screed under floor tiles and electric underfloor heating.
Tiles by area and tile size
With a 3 mm joint and 10% extra for cuts. Worked out by the tile calculator.
| Area (m²) | 300 x 300 mm | 600 x 300 mm | 600 x 600 mm | 200 x 100 mm |
|---|---|---|---|---|
| 2 | 24 | 13 | 7 | 106 |
| 4 | 48 | 25 | 13 | 211 |
| 6 | 72 | 37 | 19 | 316 |
| 8 | 96 | 49 | 25 | 421 |
| 10 | 120 | 61 | 31 | 527 |
| 15 | 180 | 91 | 46 | 790 |
Tiles, adhesive and grout
Bigger tiles need a deeper trowel notch and more adhesive per square metre; narrow joints and thin tiles take less grout. The tile calculator works out all three from the tile size, joint and trowel.
The full list for a bathroom floor
A 3 x 2.5 m bathroom floor in 300 mm tiles with backer board takes 90 tiles in 9 boxes, 9 boards and 2 bags of adhesive, according to the tiling materials calculator.
Screed and underfloor heating
Tiles need a flat, stiff base. Uneven concrete floors are screeded first, and electric underfloor heating mats go down before the tile adhesive, so size them before you buy the tiles.
Every calculator for this topic
Guides
- Common Mistakes When Tiling a Floor or Wall (UK): Waste, GroutTiling mistakes that need a second trip. A 3 × 2.5 m floor of 300 mm tiles takes 90 tiles with 10% extra, or 94 with 15%.
- Electric Underfloor Heating Cost: Running Cost and Size Chart (UK)A 4 × 3 m room with electric underfloor heating needs about 1,440 W and costs £70 a month at 6 hours a day and 27p. Charts by room size and price.
- How Many Tiles Do I Need? UK Guide with Adhesive and GroutHow many tiles you need for a floor or wall in m², with a chart for common rooms and tile sizes, plus the adhesive and grout to buy and what to check first.
- Floor Screed: How Much Sand, Cement or Ready-Mix Do I Need?How to work out the volume of a floor screed, with the sand and cement for a 1:4.5 mix or the bags of ready-mix, charts by room and depth, and drying times.
Other guides that use these calculators: Common Mistakes Laying a Concrete Base (UK): Depth, Mix, Waste · How Much Sand and Cement to Render a Wall? Bags and Tonnes (UK) · Laminate, Vinyl (LVT) or Engineered Wood Flooring: Which? · Sand and Cement Mix Ratios (UK): Concrete, Screed, Render and Mortar · Cost to Run Household Appliances: UK Table per kWh
Project planners
Planning the whole job rather than one material? These step-by-step planners put the calculators above in the order you will need them.
Frequently asked questions
How many tiles for 10 m²?
120 tiles of 300 x 300 mm with a 3 mm joint and 10% extra.
How much tile adhesive per square metre?
Roughly 3 kg/m² with a 6 mm notch for wall tiles, 4.5 kg/m² with a 10 mm notch for floor tiles and 6 kg/m² with a 12 mm notch for large formats. The bag gives the exact figure.
How much extra tile should I buy?
Ten percent for a straight layout, more for diagonal patterns or large tiles that break easily. Keep a few spares from the same batch.
Can I tile onto plasterboard in a shower?
Use cement backer board or a tanking system in wet areas; ordinary plasterboard softens if water gets behind the tiles.
Related topics
Estimates only. Quantities depend on your materials, site and supplier, so check pack sizes and coverage on the label. Check the Building Regulations and any planning rules for anything structural or close to a boundary. How we calculate.