How is the tile count worked out?

It divides the surface area by the area of one tile to get the base count, multiplies by your waste factor, then rounds up to whole tiles since you cannot buy a fraction of a tile.

How much waste should I allow?

A 10% waste allowance is typical for straight layouts; use 15–20% for diagonal patterns, large tiles, or rooms with many cuts. The default is 10%.

Is my data uploaded anywhere?

No. All calculations run entirely in your browser and nothing is sent to a server.

What units does the calculator use?

In metric mode the surface is in metres and tile size in centimetres; in imperial mode the surface is in feet and tile size in inches. The tool converts tile dimensions to match the surface area automatically.

Does it account for grout lines?

No. It uses the nominal tile size, so for very small tiles with wide grout joints the count is a slight overestimate, which is usually safe given you also add a waste allowance.

Can I use it for walls as well as floors?

Yes. The maths is identical — enter the wall's height and width as the surface dimensions instead of a floor's length and width.

Why does it round up?

You can only buy whole tiles, so the result is rounded up to the next whole tile to guarantee full coverage including the waste margin.

Tile Calculator — Gera Tools

Tile calculator — how many tiles to buy

This calculator tells you how many tiles to order for a floor or wall, including a margin for cuts and breakages. It is built for DIY renovators and trade estimators sizing up a tiling job before buying materials.

How it works

The tool computes two areas and applies a waste factor:

surface area = surface length × surface width
tile area    = tile length × tile width   (converted to surface units)
base tiles   = surface area ÷ tile area
tiles needed = ceil(base tiles × (1 + waste% / 100))

In metric mode, surface dimensions are metres and tile dimensions centimetres (converted at 0.01 m/cm); in imperial mode, surfaces are feet and tiles inches (converted at 1/12 ft/in). The base count is multiplied by the waste factor and rounded up to whole tiles, since you can’t buy a fraction.

Example

A 4 m × 3 m floor is 12 m². With 30 cm × 30 cm tiles, each tile covers 0.30 × 0.30 = 0.09 m², so the base count is 12 ÷ 0.09 ≈ 133.3 tiles. Adding a 10% waste allowance gives 133.3 × 1.10 ≈ 146.7, rounded up to 147 tiles.

Waste allowance	Typical use
10%	Straight, grid layouts (default)
15%	Larger tiles, some cuts
20%	Diagonal patterns, complex rooms

All calculations run instantly in your browser; nothing is uploaded.