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How many boxes of tiles should you buy after planning the layout?

Created by Outilo Last updated on 03/10/2026
Quick answer

Start with the number of whole tiles needed to make the layout, including the cut pieces. Add together areas using exactly the same tiles. Include a reserve if it is not already counted, then work out the number of full boxes.

Explanation

Count tiles to buy, not every cut piece

One tile may provide two cut pieces. It then counts only once in the purchase. But two pieces cannot always come from the same tile: their shape, size or pattern direction may prevent it.

Check what the result means: cut pieces, whole tiles or a quantity that already includes spares. “Source tiles” means the whole tiles used to make the pieces shown on the plan.

Combine matching products

If two rooms use exactly the same product, add their requirements before working out the boxes. Ask the supplier whether the batches, sizes and colours can be mixed.

Keep different products, skirting tiles, small decorative tiles and any left- or right-handed pieces separate. Each product needs its own order quantity.

Allow some spare tiles

A reserve covers breakage, adjustments or a later repair. Choose it to suit the job. If cuts are already included in the plan, do not automatically add another allowance for those same cuts. If the result already includes spares, do not add them again either.

The tile layout planner combines purchases before adding the reserve and rounding to boxes. Before drawing, the tile area calculator gives an initial estimate. The beginner’s guide explains the difference.

Formula / method

Boxes to buy = tiles needed, including spares ÷ tiles in one box.

If the result is not a whole number, round up: 4.75 boxes means buying 5 boxes. Use the tile count printed on the packaging. If the supplier sells by square metre or in mixed packs, check their contents before calculating.

Concrete example

Two rooms each need 17 tiles of the same product: 34 tiles altogether. For this example, you choose 10% spares, which adds 3.4 tiles. Allow 38 whole tiles.

With 8 tiles per box: 38 ÷ 8 = 4.75, so buy 5 boxes, or 40 tiles.

Calculating boxes separately for each room would give 3 boxes per room: 6 boxes and 48 tiles. Combining the requirements avoids an extra box here. The 10% reserve is an example, not a rule for every job.

Common mistake

Do not remove tiles from your order just because the drawing shows leftover pieces. First check whether those offcuts can really be reused.

For a mixed-size pack sold as one set, enough square metres does not guarantee enough pieces of each size. Check the pack contents.


Sources & methodology

Features: Outilo tile layout planner, checked on 3 October 2026. Rounding formula and order comparison: original calculations. The 10% reserve is an illustrative assumption, not an installation requirement.

This content follows Outilo's editorial guidelines.

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