Tile calculator
Estimate tiles for a room or known area: tile size, laying pattern, cutting waste, boxes, adhesive and grout.
Tile calculation
Describe the area, tile size and packaging: quantities to order are recalculated automatically.
Adhesive and grout
Additional materials
Area actually purchased
Surplus
Estimated adhesive
Estimated grout
Calculation details
Was this tool useful?
How does this tool work?
The tile calculator turns an area into a quantity you can actually buy: tiles, boxes and the resulting surplus. It starts from the dimensions of a room or from an area you have already measured, adds a cutting and breakage allowance and can estimate adhesive and grout from the manufacturer’s consumption rates.
The engine first works out the area to tile: length × width for a room, or the area you enter directly.
The cutting and breakage allowance is then added. Choosing a diagonal lay suggests a higher allowance (15% instead of 10%), which you can still change.
The order area is divided by the area of one tile, taken from the selected size, and rounded up to give the minimum number of tiles.
If you enter the packaging, as area per box or tiles per box, the result is rounded up to whole boxes and the area actually purchased is shown.
Adhesive and grout are estimated on the order area, allowance included, by multiplying it by the consumption in kg/m² that you enter.
For an 18 m² surface with 10% waste, the starting quantity becomes 19.8 m² before rounding to full boxes. Cuts, layout, laying direction and tile size can justify a different allowance.
How to use this tool
Measure the area
Room dimensions or a known area.
Choose the tile size
Use a common size or enter your own dimensions.
Adjust the allowance
Straight and diagonal lays do not usually produce the same amount of waste.
Enter the box
Area per box or number of tiles per box, as printed on the packaging.
Tile formulas
Quantities are rounded up to the next tile or box so that you never under-order.
Room area
A = length × width
For a rectangular area.
Order area
order A = A × (1 + allowance / 100)
The allowance covers cuts, breakage and tile selection.
Tile count
N = ceil(order area / area per tile)
Always rounded up to a whole tile.
The allowance depends on the layout, the number of cuts, the setting-out and the product. Replace the adhesive and grout consumption with the values of the product you choose.
Use cases
Kitchen or bathroom floor
Enter the room’s length and width, then pick the tile size.
Area already measured
Type the square metres directly when the measurements are already done, for example for a wall splashback.
Preparing an order
Turn the theoretical need into the number of boxes to buy and see the surplus before ordering.
Examples
18 m² room with 60 × 60 tiles
18 × 1.10 = 19.8 m², then 19.8 ÷ 0.36 m² = 55 tiles. 19.8 ÷ 1.44 = 13.75, so 14 boxes: 20.16 m² bought, 2.16 m² more than the area laid.
Input
Area 18 m² · 60 × 60 cm tiles · straight lay · 10% allowance · 1.44 m² boxes · adhesive 4 kg/m² · grout 0.3 kg/m²Result
19.8 m² to order; 55 tiles; 14 boxes (20.16 m²); adhesive 79.2 kg; grout 5.94 kg5 × 4 m room with 30 × 60 tiles laid diagonally
20 m² + 15% = 23 m². At 0.18 m² per tile that is 127.8 tiles, rounded up to 128, then 128 ÷ 8 = 16 boxes.
Input
Room 5 m × 4 m · 30 × 60 cm tiles · diagonal lay · 15% allowance · 8 tiles per boxResult
23 m² to order; 128 tiles; 16 boxes (23.04 m²)Tips and best practices
- Keep a few spare tiles after the job for future repairs: the same batch can be hard to find later.
- For a room with many corners, niches or cuts, increase the allowance.
- Adhesive consumption depends on the substrate, the notched trowel and the tile size; large tiles often need more.
Sources and references
Frequently asked questions
What waste allowance should I use for tiles?
10% is common for a simple straight lay. A diagonal lay or a job with many cuts may need more; the calculator suggests 15% for a diagonal lay.
Why calculate boxes rather than just tiles?
Tiles are usually sold by the box. Working in boxes shows the area you will actually buy and the surplus.
How do I work out the number of tiles?
Divide the order area by the area of one tile, then round up to the next whole number: 19.8 m² ÷ 0.36 m² gives 55 tiles of 60 × 60 cm.
Is the adhesive quantity exact?
The engine applies the consumption in kg/m² that you enter to the order area. The manufacturer’s data sheet remains the reference.
Does a diagonal lay need more allowance?
Usually yes, because there are more cuts along the edges. The suggested value is indicative and can be changed.
Related tools
Keep going with these tools
Tools similar or complementary to this one.
Similar tools
Calculate paintable area, litres required and paint containers to buy.
Construction & renovationFeaturedUse this tool
Calculate packs, underlay, surplus and skirting boards for your floor.
Construction & renovationUse this tool
Estimate decking boards, joists, fixings and waste.
Construction & renovationUse this tool
Read next
GuideBest practicesBeginner
How many tiles and boxes should you buy?
How many tiles and boxes should you buy?
30 August 20262 min
GuideBest practicesBeginner
Plan a project: how to calculate the right material quantities?
A practical method for turning project dimensions into quantities to buy: areas, volumes, waste allowances, packaging and final checks.
30 August 20263 min
TutorialBest practicesBeginner
Plan a construction project: calculate materials before buying
A practical method for estimating concrete, screed, bricks, render, fencing, decking and other materials before you order.
30 August 20264 min
GuideBest practicesBeginner
How much paint does a room need?
Calculate paintable area, coats, coverage and the cans to buy.
30 August 20262 min