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Tile count with a wastage allowance
Divide the surface area by the tile area, then multiply by one plus the wastage rate written as a decimal. Round the result up to a whole tile.
The Formula
N = (A / a) x (1 + w)
Divide the surface area by the tile area, then multiply by one plus the wastage rate written as a decimal. Round the result up to a whole tile.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| N | Tiles to order | count | 12 / 0.09 = 133.33333333333334 exact tiles before wastage, and 146.66666666666669 after it. |
| A | Surface area to cover | square units | 12 square metres in the worked example. |
| w | Wastage rate | decimal | Ten percent, entered as 0.1, which lifts the count to 146.66666666666669 tiles. |
What Each Symbol Means
Ncount
Tiles to order
12 / 0.09 = 133.33333333333334 exact tiles before wastage, and 146.66666666666669 after it.
Asquare units
Surface area to cover
12 square metres in the worked example.
wdecimal
Wastage rate
Ten percent, entered as 0.1, which lifts the count to 146.66666666666669 tiles.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate tile count page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Tile Count, filed under Everyday Life. Every number the guide produces comes from substituting into this one line.