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Tile Calculator

Enter the size of the area, tile dimensions and product packaging details to estimate how many tiles, boxes and adhesive bags you may need, including an allowance for cuts, breakages and spare tiles.

Calculate tiles

This calculator estimates tile quantity, boxes and adhesive from the measurements and product coverage you enter. Check tile and adhesive packaging, manufacturer data sheets and installation requirements before buying or fitting materials. Complex layouts, uneven surfaces, cuts, movement joints, waterproofing and substrate preparation can change what is needed.

Surface type
Floor areas typically use a full bed of adhesive under each tile.
Measurement units

Area to tile

m²
Untiled areas within the space — doors, windows, fixed units or bath panels — as one total area.

Your tiles

The actual physical tile size, excluding the grout joint unless the packaging says otherwise.
How your tiles are packaged
Cuts and wastage
Extra tile allowance for cuts, breakages, pattern matching and small mistakes. Defaults are a starting point, not a guarantee — they do not replace your own layout plan.
%
Extra tiles to keep aside for future repairs, applied after the waste allowance.
Tile adhesive (optional)

Use coverage stated on adhesive packaging or manufacturer data sheet. Adhesive use depends on trowel notch, bed thickness, tile size/type, surface flatness, back-buttering and installation method.

Add material costs (optional)
Tiles to buy
37 tiles
Gross area
12 m²
Area excluded
0 m²
Net area to tile
12 m²
Tiles before waste
34 tiles
Tiles per box
4 boxes
Coverage purchased
14.4 m²

Includes a 10% waste allowance.

3 tiles extra after rounding up to full boxes.

Tile and adhesive estimates are approximate. Check your chosen tile dimensions, packaging and adhesive product data before ordering.

This calculator gives an order-planning estimate only. It does not produce a cutting plan, tile layout, grout estimate, adhesive or trowel recommendation, substrate or waterproofing guidance, manufacturer installation instruction, labour quote or building or safety compliance result. For installation guidance, consult tile and adhesive manufacturer instructions or a qualified installer.

How to use this calculator

  1. Choose Floor or Wall, and Metric or Imperial units.
  2. Enter the length and width of the area to tile, and any untiled area to exclude.
  3. Enter the tile length and width.
  4. Choose how your tiles are packaged, and enter the tiles per box or the box coverage.
  5. Pick a layout for a suggested waste allowance, and add a spare percentage if you want one.
  6. Optionally add adhesive coverage or consumption details, and material costs.
  7. The calculator estimates the tiles, boxes and adhesive bags to buy.

How is the number of tiles calculated?

The calculator finds the net area to tile, then works out how many tiles cover it before adding a waste allowance for cuts and breakages and an optional spare allowance. The result is rounded up to a whole tile, and then to a whole box if you buy tiles by the box.

net area = gross area − excluded area
  • tile area = tile length × tile width
  • area after waste = net area × (1 + waste ÷ 100)
  • order area = area after waste × (1 + spare ÷ 100)
  • tiles to buy = order area ÷ tile area, rounded up

Example: a 4 m × 3 m floor, 600 × 600 mm tiles, 10% waste, 10 tiles per box

  1. 4 × 3 = 12 m² net area, with nothing excluded.
  2. Each tile covers 0.6 × 0.6 = 0.36 m².
  3. 12 × 1.10 = 13.2 m² after a 10% waste allowance, with no spare tiles added.
  4. 13.2 ÷ 0.36 = 36.67, which rounds up to 37 tiles to buy.
  5. 37 ÷ 10 = 3.7, which rounds up to 4 boxes — 40 tiles purchased in total.

Why is adhesive calculated separately from tile waste?

Tile waste and spare tiles allow for cuts, breakages and future repairs in the tiles themselves. An offcut from a cut tile does not usually need its own extra bed of adhesive, so sizing adhesive from the larger tile order area would overstate what is needed. Instead, adhesive is calculated from the net area to tile plus its own contingency percentage, which you set independently — typically a smaller allowance for spreading losses and an uneven substrate rather than for cutting waste.

Metric and imperial tile measurements

The calculator converts every measurement into a single internal area in square metres before showing results in the selected measurement system, so metric and imperial results can never disagree. Imperial mode uses feet and inches for dimensions, square feet for area, and pounds for adhesive weight.

Example: a 10 ft × 12 ft floor, 12 in × 12 in tiles, 10% waste, 10 tiles per boxgives 120 ft² of net area, 132 tiles to buy, and 14 boxes.

How much tile waste should I allow?

A waste allowance helps cover cuts, breakages, pattern matching and small mistakes. The layout presets in the calculator — straight or simple grid, offset or running bond, diagonal, and herringbone or patterned — are common starting points, not guarantees. A room with many corners, pipework or a large-format tile can need a higher allowance regardless of the layout.

What this calculator does not cover

This is an order-planning estimate only. It does not produce a cutting plan, a tile layout, a grout estimate, an adhesive, trowel, substrate or waterproofing recommendation, a manufacturer installation instruction, a labour quote, or a building or safety compliance result. Complex layouts, uneven surfaces, cuts, movement joints, waterproofing and substrate preparation can all change what is needed — check tile and adhesive packaging, manufacturer data sheets and installation requirements before buying or fitting materials.

Frequently asked questions

How many tiles do I need for a floor or wall?

Multiply the area length by its width to get the gross area, subtract any untiled area such as doors, windows or fixed units, then divide the net area by the area of one tile. Add a waste allowance for cuts and breakages, and an optional spare percentage, before rounding up to a whole tile.

What waste allowance should I use for tiles?

A straight, simple grid typically needs around 10% extra for cuts and breakages. An offset or running-bond layout is closer to 12%, a diagonal layout around 15%, and herringbone or another patterned layout around 20%. These are starting points, not guarantees — a complex room shape or a large-format tile can need more.

Should I buy spare tiles?

Keeping a small number of spare tiles — commonly 5% to 10% on top of the waste allowance — means a future repair or a damaged tile can be matched from the same batch and dye lot, rather than relying on a discontinued product later.

How do I work out how many boxes of tiles I need?

If you know how many tiles come in a box, divide the tiles to buy by that number and round up. If the box states its coverage in area instead, divide the order area (after waste and spares) by the box coverage and round up. Rounding up to a full box means you usually buy a few tiles more than the bare minimum.

How much tile adhesive do I need?

Use the coverage or consumption rate stated on the adhesive packaging or manufacturer data sheet. Enter either the area one bag covers, or the consumption rate per unit area plus the bag weight, and the calculator estimates the bags needed for the net area plus your chosen contingency.

Why doesn't the adhesive calculation use the tile waste allowance?

Tile waste covers cuts and breakages in the tiles themselves — offcuts do not normally need extra adhesive coverage. Adhesive is calculated from the net area to tile plus its own independent contingency, which you can set separately, rather than from the larger tile order area.

Does it matter if I am tiling a wall or a floor?

The area and tile maths is the same for a wall or a floor. Wall tiling commonly uses smaller tiles and a thinner adhesive bed than a floor, so check the adhesive coverage stated for your specific tile and surface — the calculator uses whatever coverage or consumption rate you enter either way.

Does this calculator include grout?

No. Grout quantity depends on the joint width, tile thickness and grout type, none of which this calculator collects. It estimates tiles, boxes and adhesive only.

Does this calculator give me a cutting plan or tile layout?

No. It estimates order quantities only. It does not lay out where cuts fall, plan a pattern, or account for movement joints, substrate preparation or waterproofing — check manufacturer instructions or a qualified installer for those.