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Tile Calculator

Work out how many floor or wall tiles you need from the room area, the tile size, the grout gap, and a waste allowance, then see how many boxes that is to buy.

Units

Room size

Tile size

The grout gap is the spacing between tiles. Set it to zero for a tight joint.

Box size and waste

Around 10% suits a straight grid. Use about 15% for a diagonal layout and 20% or more for herringbone. Everything runs in your browser. Nothing is uploaded.

Tiles needed
144 tiles
to cover 12 m² with a 10% waste allowance
15
Boxes to buy (10/box)
13
Extra tiles for cuts
13.77 m²
Total area covered
150
Tiles in boxes (19 spare)
12 m²
Room area
0.09 m²
Tile footprint each

This is an estimate. The real total shifts with the layout, the cut edges around the room, and breakages, so keeping a spare box for future repairs is sensible.

How to calculate how many tiles you need

  1. Choose your units

    Pick meters with centimeter tiles or feet with inch tiles so every measurement uses the same system.

  2. Enter the room and tile size

    Type the room area or its length and width, then the width and height of a single tile and the grout gap between tiles.

  3. Set the box size and waste

    Enter how many tiles come in a box and a waste percentage for the tiles you will cut and break.

  4. Read how much to buy

    See the tiles needed, the number of boxes to buy, the total area they cover, and the extra tiles left for cuts.

Why use this tool

Room area or dimensions

Enter the floor or wall area directly, or type the length and width and let the tool multiply them for you.

Grout gap included

The width of the grout line is added to every tile, so the count reflects the real space each tile takes up, not just the bare tile.

Boxes, not just tiles

Tell the tool how many tiles come in a box and it rounds up to whole boxes, since that is how tile is actually sold.

Waste allowance for cuts

A waste percentage covers the tiles you cut around the edges and the ones that break in handling, with sensible defaults for straight and diagonal layouts.

Metric or imperial

Switch between meters with centimeter tiles and feet with inch tiles at any time. Your measurements convert automatically so the result stays the same.

Runs entirely in your browser

Every calculation happens on your device as you type. Nothing is uploaded, stored, or logged.

About this tool

This tile calculator works out how many tiles you need to buy for a floor or wall, and how many boxes that comes to. Give it the area of the room or its length and width, the size of one tile, the width of the grout gap between tiles, and a waste percentage for cuts and breakages. It adds the grout line to each tile to get the real space a tile occupies, divides the room area by that footprint, adds your waste allowance, and rounds up to whole tiles and whole boxes so you leave the shop with enough to finish.

Use it before any tiling job to avoid a second trip for one missing box, or a pile of leftovers you cannot return. Work in meters with centimeter tiles and millimeter grout, or in feet with inch tiles and inch grout, and switch between the two at any time without re-measuring. The default ten percent waste suits a straight grid; raise it to around fifteen percent for a diagonal layout and twenty percent for herringbone or busy patterns. For turning odd measurements into an area the unit converter and percentage calculator help, and the paint calculator covers the walls once the floor is done.

Treat the totals as a close estimate. Real jobs vary with the layout, the number of cut edges around the room, and how many tiles crack during handling, so keeping a spare box for future repairs is sensible. Every figure is worked out in your browser as you type, and nothing you enter is uploaded, stored, or logged.

Frequently asked questions

How does the tile calculator work?
It adds the grout gap to the width and height of one tile to get the real space each tile takes up on the floor, then divides the room area by that footprint. It multiplies the result by your waste percentage, rounds up to whole tiles, and rounds again to whole boxes using the tiles-per-box figure you enter.
How much waste should I add?
Around ten percent is a common allowance for a straight grid layout. Raise it to roughly fifteen percent for tiles set on a diagonal, and to twenty percent or more for herringbone and other busy patterns, since those create more cut and offcut tiles around the edges.
Can I enter the area instead of length and width?
Yes. Switch the room input to total area and type the number you measured, in square meters or square feet. This is useful for L-shaped rooms, sloped areas, or when you are only tiling part of a floor or wall.
What does the grout gap do to the count?
The grout gap is the spacing left between tiles. Adding it to each tile makes every tile occupy a little more space, so a larger gap means slightly fewer tiles across the same area. Set it to zero for tiles laid with no visible joint.
Why do I end up buying whole boxes with extra tiles?
Tile is sold by the box, so the tool rounds the tiles needed up to complete boxes and shows how many spare tiles that leaves. Those spares double as your cut allowance and a small reserve for future repairs, since dye lots change and an exact match later is not guaranteed.
Is my data uploaded anywhere?
No. Every measurement and result stays on your device. All calculations run in your browser as you type and nothing is sent to a server, stored, or logged.

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