How to use this calculator
- Choose the shape of the area, or enter a total area if you already have one.
- Enter the width and length of a single tile in inches.
- Pick the layout. A straight lay needs the least extra, while diagonal and herringbone patterns waste more tile in cuts.
- Enter the number of tiles in a box to see how many boxes to order.
How the numbers are calculated
The calculator finds the area of one tile by multiplying its width by its length in inches and dividing by 144, since a square foot has 144 square inches. It then divides your floor area by that number to get the tiles needed with no waste.
The waste percentage is then added and the result is rounded up. Ten percent suits a simple straight lay, 15% suits diagonal or brick patterns, and 20% suits herringbone or a small room with many cuts. Boxes are the tile count divided by tiles per box, rounded up.
Worked example
A floor 10 ft by 8 ft has an area of 80 sq ft. A 12 in by 12 in tile covers 1 sq ft, so you need 80 tiles with no waste. Adding 10% gives 88 tiles. With 10 tiles in a box that is 9 boxes, or 90 tiles.
Tips before you buy
- Buy every box from the same production lot. Shades can differ between batches, and you cannot always match them later.
- Keep a few spare tiles after the job for repairs. Discontinued styles are hard to replace.
- Large-format tiles need a very flat floor, and they often waste more material at the edges.
- Lay a row of tiles dry across the room before you start so you can avoid thin cut tiles along a wall.
- Wide grout joints change the count slightly. For small tiles with wide joints, ask your supplier for coverage per box.
Frequently asked questions
How many 12 by 12 tiles do I need for 100 square feet?
You need 100 tiles with no waste, or about 110 with a 10% allowance for cuts.
How many 6 by 6 tiles are in a square foot?
Four. A 6 inch tile covers a quarter of a square foot, so 100 square feet takes 400 tiles before waste.
How many 12 by 24 tiles cover 100 square feet?
Each tile covers 2 square feet, so you need 50 tiles with no waste and about 55 with a 10% allowance.
How much extra tile should I buy?
Ten percent is the usual minimum. Choose 15% to 20% for diagonal layouts, herringbone patterns or small rooms.
Quick answers
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These results are estimates for planning purposes. Material sizes, densities and local requirements vary, so confirm quantities with your supplier or a qualified contractor before ordering.
Last updated October 11, 2026.