Tile Calculator
Calculate tiles needed with grout gaps and waste factor for floors and walls.
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Quick Tip
Enter the room length and width in feet.
About This Tool
Why use Tile Calculator?
Enter the room dimensions and the tile size and this calculator returns how many tiles you need, including the grout gap and a waste allowance. Tile size is taken in inches and includes the grout joint, so a 12-inch tile with a 1/8-inch gap effectively occupies 12.125 inches.
For a 10 ft × 12 ft floor (120 sq ft) with 12-inch tiles and a 1/8-inch gap, each tile covers 1.02 sq ft, so 118 tiles fit exactly and a 10% waste factor takes the order to 130 — about 13 boxes at ten tiles each. Use 10% for straight layouts and 15% for diagonal or herringbone patterns, where cuts are larger.
Key Benefits
Grout gap included
The joint is added to the tile size, which is what stops an order coming up short on a large floor.
Waste factor you control
Exact and with-waste counts are both shown, so you can see what the allowance is costing.
Box estimate
Tiles are converted into approximate boxes of ten, which is how most are sold.
How to use Tile Calculator
- 1
Enter the room length and width in feet.
- 2
Enter the tile length and width in inches.
- 3
Set the grout gap — 1/8 inch (0.125) is common for floors, 1/16 for wall tiles.
- 4
Choose a waste factor and read the number of tiles and boxes to order.
Best use cases
Order floor tiles for a bathroom or kitchen.
Compare how tile size changes the count and the number of cuts.
Budget a tiling job before visiting a supplier.
Work out how many spare tiles to keep for future repairs.
Tile Calculator FAQs
How much waste should I allow for tiles?
10% for a standard straight layout, 15% for diagonal or herringbone patterns, and more in rooms with many angles or fixtures.
What grout gap should I use?
1/8 inch (3 mm) is typical for floor tiles and 1/16 inch (1.5 mm) for wall tiles. Rectified tiles can go tighter; rustic and handmade tiles need wider joints.
Should I buy spare tiles?
Yes. Keep a few from the same batch: colours vary between production runs, so a later repair with new stock rarely matches.
Does tile size change how many I need?
It changes the count and the amount of cutting. Large tiles cover more area with fewer joints but waste more at edges; small tiles produce less waste but take longer to lay.
Related Construction Tools
More free construction tools that work well alongside tile calculator.