Why buy extra beyond the wastage?

Shade varies between production batches, so a repair years later rarely matches. A spare box from the same batch is cheap insurance.

Construction & Homefinishing

Tile Calculator

Tile count from floor or wall area, with wastage. Ten percent is the usual allowance and a diagonal or herringbone layout needs more, because every edge cut produces an offcut you cannot use.

Also called: tiles needed calculator, floor tile quantity.

Tiles

61.11

61.11 tiles for 20 m² over 1 coat(s), including 10% wastage.

Area after deductions (m²)

Area across all coats (m²)

Before wastage

55.56

Area one unit covers (m²)

0.36

How this is calculated

Method and background

How this is calculated

Area divided by the area one tile covers, plus wastage. The wastage figure carries all the judgement: a straight layout in a rectangular room wastes little, while a diagonal layout, a patterned tile that has to be aligned, or a room with many alcoves can waste fifteen to twenty percent. Buying from the same batch matters too, since shade varies between production runs.

quantity = area * coats / coverage per unit, plus wastage

A: Net area (m2)
c: Coats (count)
r: Coverage per unit (m2)
s: Wastage (decimal)

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

a room in 600x600 tiles

Length (m): 5
Width or height (m): 4
Or enter the area directly (m²): 0
Openings to deduct (m²): 0
Area one tile covers (m²): 0.36
Coats or layers: 1
Wastage: 10%

Tiles61.11

20 / 0.36, plus a tenth

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a larger tile needs fewer

Length (m): 5
Width or height (m): 4
Or enter the area directly (m²): 0
Openings to deduct (m²): 0
Area one tile covers (m²): 0.64
Coats or layers: 1
Wastage: 10%

Tiles34.38

boundary

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no area needs no tiles

Length (m): 0
Width or height (m): 0
Or enter the area directly (m²): 0
Openings to deduct (m²): 0
Area one tile covers (m²): 0.36
Coats or layers: 1
Wastage: 10%

Tiles0

degenerate case

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Method and limits

What it assumes

Grout joints are absorbed into the tile area, which is close enough at normal joint widths.

What it deliberately does not model

Rectified tiles with very narrow joints fit slightly more per square metre.
It does not plan the layout, so a room needing a full tile at a sightline may want more.

Formula version 1.0.0 · definition 1.0.0 · United States · Report a problem with this calculator

Frequently asked questions

Why buy extra beyond the wastage?: Shade varies between production batches, so a repair years later rarely matches. A spare box from the same batch is cheap insurance.