BYTETOOLS

Tile Calculator

Calculate how many tiles and boxes you need for floors or walls from tile size, grout joint width and a waste allowance, across as many surfaces as you like.

Surfaces to tile (ft)

120.00
Total surface (sq ft)
132.00
With 10% waste (sq ft)
130
Tiles needed
13
Boxes to buy
1.0209
Area per tile incl. joint (sq ft)
$390.00
Estimated tile cost

Each tile is treated as (tile width + joint) × (tile length + joint), so the grout lines are counted. Surface area is divided by that figure after adding the 10% waste allowance selected above. Buy from a single batch and keep spares — shade varies between production lots. These are estimates, not a tiler's measured take-off.

What is the Tile Calculator?

The ByteTools Tile Calculator tells you how many tiles to order. Add each surface you are tiling, enter your tile size and grout joint width, pick a layout, and it works out the effective area each tile covers, the number of tiles required including waste, the boxes to buy and the cost.

  • Unlimited surfaces added in one calculation
  • Grout joint width folded into the effective tile area
  • Waste allowance by layout: 10%, 15% or 20%
  • Tile count, boxes to buy and total cost
  • Imperial (feet and inches) and metric (metres and millimetres)
  • Private and instant — everything runs locally

How to use the Tile Calculator

  1. 1

    Choose imperial or metric and add one row for each surface you are tiling.

  2. 2

    Enter the tile width, tile length and the grout joint you plan to use.

  3. 3

    Pick the layout — straight, diagonal or herringbone — to set the waste allowance.

  4. 4

    Enter how many tiles come in a box and the price per box.

  5. 5

    Read the tile count, the number of boxes and the estimated cost.

About the Tile Calculator

The ByteTools Tile Calculator tells you how many tiles to order. Add each surface you are tiling, enter your tile size and grout joint width, pick a layout, and it works out the effective area each tile covers, the number of tiles required including waste, the boxes to buy and the cost.

Because the grout joint is added to the tile dimensions, the count reflects how tiles actually sit on a wall or floor rather than assuming they butt together. Multiple surfaces — a floor plus a splashback plus a shower wall — can all be added to the same job.

Both imperial and metric are supported and everything is computed in your browser with nothing uploaded. Cuts, pattern layouts and awkward corners all change the real number, so use the result as an estimate and confirm anything large with your tiler.

Frequently asked questions

How many tiles do I need per square metre?

Divide one square metre by the area of a single tile including its grout joint. A 300 × 300 mm tile with a 3 mm joint effectively occupies 303 × 303 mm, or 0.0918 m², so you need about 10.9 tiles per square metre before waste is added.

How much extra tile should I buy for waste?

Ten percent is the standard allowance for a straightforward straight lay. Diagonal and brick-offset patterns push it to about 15%, and herringbone or a room full of angles can reach 20%. This calculator applies whichever figure matches the layout you select.

Do you include the grout lines when counting tiles?

Yes. Each tile is treated as its own size plus one joint width in each direction, which is how tiles actually repeat across a surface. Ignoring the joint slightly over-counts tiles on small formats and mosaics.

Should I buy all my tiles at once?

Yes, and from the same batch or shade number if you can. Tile colour varies measurably between production runs, so a box bought later to finish a job can be visibly different. Keeping a few spare tiles from the original batch also makes future repairs invisible.

Is this an exact tile count?

It is a close estimate. Real jobs depend on where the layout starts, how cuts fall at the edges, and how many part tiles can be reused elsewhere. Treat the number as an order quantity to discuss with your supplier rather than a guaranteed figure.

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