TILE BUYING ADVICE
Price per box vs price per m²: which tile deal is cheaper?
You have found two tiles you like. One has a lower price per square metre; the other has a cheaper box. Neither figure tells you what you will pay for your room. The useful comparison is the quantity you must buy, priced at checkout.
By eToolPlus · Published
Start with the same net tiled area. Add a layout-appropriate allowance, round each product up to its selling unit, then include delivery and any different installation expenses. Below, the cheaper tile changes twice without either advertised price changing.
Read three numbers before judging the price
Record the selling unit, the actual price of that unit and its coverage. A box costing £30 might cover 1 m² or 1.5 m²: those prices are £30/m² and £20/m² respectively. The cheaper box is not automatically the better unit price, and the better unit price is only the start of an order comparison.
Use the exact product's stated box coverage. If only tile dimensions and a box count are available, check the manufacturer's coverage before paying. Do not assume all 60 × 60 cm products have the same number of tiles in a box.
Price per m² = box price ÷ box coverage in m².
Box price = price per m² × box coverage in m².
A £28.80 box covering 1.44 m² costs £20/m²: £28.80 ÷ 1.44 = £20. Conversely, tiles advertised at £20/m² and sold in 1.44 m² boxes have a calculated box price of £28.80. Use the actual selling price if the retailer rounds prices or applies a discount.
A sample price can be much smaller than the price of a saleable tile or box. Confirm that the number you record buys the product you intend to install, and that both quotes include or exclude the same charges.
For prices per square foot, use coverage in square feet throughout. One m² is approximately 10.764 sq ft, so £20/m² is about £1.86/sq ft. These are two expressions of the same price, not a discount. Keep full precision for calculations and round the final money total for display.
Two fictional orders: how box rounding changes the winner
Our example has a net tiled area of 12 m². With an illustrative 10% allowance, the purchasing target is 13.2 m². Both products are assumed suitable for the job and sold only in full boxes. These invented prices demonstrate the method; they are not current offers or a survey of tile prices.
| Comparison | Tile A | Tile B |
|---|---|---|
| Advertised price per m² | £20 | £21 |
| Coverage per box | 1.44 m² | 1.10 m² |
| Price per box | £28.80 | £23.10 |
| Boxes needed, rounded up | 10 | 12 |
| Purchased coverage | 14.40 m² | 13.20 m² |
| Tile material total | £288 | £277.20 |
Tile A needs 13.2 ÷ 1.44 = 9.17 boxes, rounded up to 10. Tile B needs exactly 12 boxes. Although Tile B costs £1 more per m², its tile order is £10.80 cheaper because the packaging fits this project's target coverage more closely.
Notice the difference between waste allowance and box surplus. The allowance increased the target from 12 to 13.2 m². Tile A's packaging then added a further 1.2 m² beyond that target. Tile B has no box surplus in this example, but its order still includes the original 10% allowance.
To see what the room actually costs to cover, divide the order total by the net tiled area. Tile A is £288 ÷ 12 = £24 per installed m² in tile material; Tile B is £277.20 ÷ 12 = £23.10. This comparison includes purchased waste and surplus, but excludes labour and delivery. Dividing the total by purchased coverage would simply reproduce the advertised unit price and hide the effect of surplus.
Find the delivery price that erases the saving
Now suppose delivery is £10 for Tile A and £25 for Tile B. Tile A's delivered total becomes £298, while Tile B's becomes £302.20. Tile A is now £4.20 cheaper overall.
You do not need to guess whether the delivery difference matters. Tile B's material saving is £10.80, so it can absorb at most £10.80 more delivery cost before the orders tie. With Tile A delivery fixed at £10, Tile B ties at £20.80 delivery. Below that it wins; above that Tile A wins, assuming all other costs match.
Maximum delivery for the cheaper material order = the other order's delivery + the material saving. Include collection expenses in the same comparison if you intend to collect instead.
If free delivery requires another box, compare the extra box price with the delivery charge avoided. Buying a £28.80 box solely to remove a £10 delivery fee increases the bill by £18.80. It may still be useful stock, but it is not a cash saving on that order.
For a complete budget, obtain quotes for any installation expenses that differ between the products. Keep tax treatment consistent and enter each expense once. Never add a separate supply cost that is already included in an installer’s quote.
A small measurement change can add a whole box
Keep the same products and allowance, but increase the net area from 12 to 12.1 m². The target becomes 13.31 m². Tile A still needs 10 boxes, costing £288. Tile B now needs 13 boxes, costing £300.30. Tile A becomes £12.30 cheaper in tile material alone.
This happens because Tile B's original order sat exactly on a box boundary. Recheck dimensions, returns and tiled recesses before using a narrow saving to choose a product. For each candidate, calculate with the area you actually intend to tile rather than rounding the room area down.
The 10% allowance here is a comparison input, not a promise that it will suit your cutting plan. Keep it consistent to isolate packaging differences; then revise each product's final allowance if the installer expects different cutting losses. Do not reduce necessary material simply to make a quotation look cheaper.
Reproduce the comparison with your own prices
- Open the tile calculator, choose Total area and enter 12 m². Leave excluded area at 0 for this example.
- Choose 10% waste and Coverage per box. Enter Tile A's 1.44 m² coverage and its actual tile dimensions.
- Choose Per m² pricing and enter 20, or choose Per box and enter 28.80. Either gives the same material total.
- Record the result, then repeat with Tile B's dimensions, 1.10 m² box coverage and £21/m² or £23.10 per box. Keep your surface area and waste allowance the same.
- For a wider budget, enable installation and enter your own labour quote, delivery and other expenses. Avoid counting an expense twice.
The calculator saves one current project in your browser. Note each product's result before changing inputs; it does not save a separate comparison for each product.
Take this comparison sheet to the supplier
Record one set of these details for each product. Ask for the full-box checkout total when a displayed unit price does not make the selling quantity clear.
| Record | Question it answers |
|---|---|
| Exact product, size and finish | Am I comparing the product that will actually be ordered? |
| Selling unit, price and box coverage | What quantity does the displayed price buy? |
| Net area, allowance and full-box count | Does the order include the project's measured requirements? |
| Delivery or collection cost | Does the material saving survive the cost of getting it home? |
| Return eligibility and any fees | Can surplus be returned, and what are the conditions? |
| Installer's product-specific quote | Are labour and supplies comparable and counted once? |
Treat a possible surplus refund separately from the upfront budget. Ask the supplier about unopened boxes, partial boxes, sale items, return deadlines and charges; do not assume a refund when calculating what you need to pay now. Record any spare tiles you intend to keep before deciding what is genuinely surplus.
- Selling unit: does the displayed price buy one tile, one box or one square metre?
- Box coverage: use the coverage for that exact product and package.
- Waste: choose an allowance for your layout and desired spares. The 10% used here is an example.
- Full-box quantity: check whether the supplier sells full boxes or offers individual tiles.
- Final total: compare the same scope, including delivery and installation expenses where relevant.
- Product suitability: confirm the tiles suit the intended floor, wall or wet area before comparing on price.
How this guide was checked
The worked orders were calculated with eToolPlus's tile calculation function using the stated area, allowance, box coverage and price. Money is displayed to two decimal places. The comparison assumes the stated coverage is usable, whole boxes are purchased and the example charges are final amounts in the same currency.
For broader product selection, see B&Q's tile guide and Wickes' tiles buying guide. Those guides provide product context; the fictional order comparisons and break-even calculations on this page are our own worked examples. Use the specific product and seller's terms for your purchase.
Found a calculation issue? Send us the inputs and the result so we can check it.