Floor Tile Calculator (Tiles, Boxes and Cost)
Find how many floor tiles and boxes you need. Enter the room size, tile size and grout gap to get the tile count with waste, boxes, covered area and cost.
The joint between tiles.
Allowance for cuts and breakage.
Enter the area to tile and the tile size.
About the floor tile calculator
The Floor Tile Calculator tells you how many floor tiles and how many boxes to order for a room. Type the room as a length and a width, each in its own unit, or enter the floor area directly if the room is not a simple rectangle. Then enter the tile size, the grout gap and a waste allowance. You get the net tile count, the number to buy, the boxes if you give a box size, the area the order will cover in square feet and square metres, and the cost if you add a price per box or per tile.
It is the same calculator as the general Tile Calculator, set up for floors. Because floor tiles are often large and are laid on a surface that cannot be adjusted once the adhesive sets, it pays to get the count right before you shop.
How to work out floor tiles
Steps
- Measure the room at its longest and widest points and enter the length and width. For an L-shaped room, split it into rectangles, add the areas, and enter the total in the direct area field.
- Enter the tile width and tile height. Floor tiles range from 12 in squares to 24 in or 60 cm squares and long planks.
- Keep the grout gap at 1/8 in (about 3 mm) unless your tile maker recommends another. Rectified large-format tiles are often laid with 2 mm or less.
- Set the waste allowance: 10 percent for a straight layout, 15 percent or more for diagonal.
- Add the tiles per box from the carton to get whole boxes.
- Read the tiles to buy, the boxes and the covered area.
Formulas
Floor tile count
Each tile and its joint form one grid cell:
For floor area and waste fraction :
Boxes are divided by the tiles per box, rounded up. The covered area is the tiles actually bought times .
Worked examples for floors
Living room. A 10 ft by 12 ft room is 120 square feet. With 12 in tiles and a 1/8 in gap, one cell is 1.021 square feet, so you need 118 tiles net. With 10 percent waste, buy 130 tiles, or 13 boxes of 10.
Large-format kitchen. A 14 ft by 16 ft kitchen is 224 square feet. With 24 in tiles and a 3/16 in gap (0.1875 in), a cell is 585.04 square inches. That gives 56 tiles net and 61 to buy with 10 percent waste. At 4 tiles per box, order 16 boxes, which means 64 tiles and about 260 square feet of coverage.
Diagonal metric floor. A 5 m by 4 m floor is 20 square metres. With 60 cm tiles and a 2 mm gap, one cell is 0.3624 square metres, so 56 tiles net. A straight layout with 10 percent waste needs 61 tiles. Laid on the diagonal with 15 percent, buy 64.
Layout tips that affect the count
Diagonal tiles waste more because every row ends in a triangle cut from a full tile. Large-format tiles waste more too, since a single cut at a wall leaves a big offcut that rarely fits elsewhere. Start from the centre of the room, not a corner, so the border cuts at opposite walls are equal and no thin sliver ends up by a doorway. A dry layout of one row before mixing adhesive shows where cuts fall.
Subfloor flatness and tile size
Large tiles need a flat subfloor. As a rule, most manufacturers ask for no more than about 1/8 in of variation over 10 ft for tiles with an edge over 15 in. A flat floor is one thing the calculator cannot tell you, but leveling compound adds depth you may need to budget for separately. Find the volume of compound or concrete with the Concrete Calculator.
Doors, closets and fixtures
Run tiles into a doorway to the middle of the closed door, and include the closet floor if it will be tiled. Subtract areas such as built-in tubs or fixed cabinets, then enter the net area in the direct area field. The Area Calculator finds the area of each shape.
Privacy
Nothing is uploaded; every calculation runs in your browser and never leaves your device.
Related tools
For walls, a backsplash or a shower, use the Wall Tile Calculator. To compare prices between two tile products, the Unit Price Calculator gives a cost per square foot. If a supplier quotes in square metres, the Area Converter converts to square feet.
Frequently asked questions
How many floor tiles do I need for a 10 ft by 12 ft room?
With 12 in tiles and a 1/8 in grout gap you need 118 tiles net for 120 square feet. Adding 10 percent for cuts and breakage gives 130 tiles to buy, which is 13 boxes at 10 tiles per box.
How much extra should I buy for a diagonal floor layout?
Allow 15 percent or more. On a 5 m by 4 m floor with 60 cm tiles and a 2 mm gap, a straight layout with 10 percent waste needs 61 tiles, while a diagonal layout with 15 percent needs 64.
Do large-format floor tiles need more waste?
Often yes. A cut at a wall leaves a large offcut that may not fit anywhere else. For 24 in tiles or larger, consider 12 to 15 percent, and lay out the first row dry to see where the cuts fall.
Where should I start laying floor tile?
Work out from the centre of the room. Snap lines through the midpoints of opposite walls and dry-fit a row, then shift the starting line so the border cuts at both walls are equal and not thinner than about half a tile.
How flat does a subfloor need to be for floor tile?
Many manufacturers ask for no more than about 1/8 in of variation over 10 ft for tiles with an edge over 15 in. Smaller tiles tolerate more. Check the tile maker's installation guide for the exact figure.
How do I enter an L-shaped room or a room with a closet?
Split the floor into rectangles, add their areas, and type the total into the direct area field. Subtract any area that will not be tiled, such as a fixed cabinet, before you enter it.
Is my data sent anywhere?
No. The floor tile counts and cost sums run in your browser, so your room dimensions and prices are never uploaded or stored on a server. They stay on this device and are not shared with anyone.