How many extra tiles should I buy?
15% is standard for rectangular floors. Complex layouts or large format tile may need 18–20%.
How Many Tiles Do I Need?
Tile projects fail at the store when you buy too few boxes. Enter room dimensions, 15% waste for cuts and breakage, and sq ft per carton — we give you a box count rounded up with no guesswork.
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Default 15%
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Tile box counts vs individual pieces
Retail tile is sold by the box, typically 10–15 sq ft per carton for floor tile. Dividing total sq ft (with waste) by box coverage and rounding up is the only reliable method.
A 10×10 bathroom floor is 100 sq ft. At 15% waste that is 115 sq ft. With 12 sq ft per box, you need 10 boxes — not 9.
Cuts, breakage, and layout complexity
Toilet flanges, floor drains, and door casings turn whole tiles into scrap. Large-format tile breaks more during handling — add extra if this is your first install.
See large format tile tips for handling, lippage, and layout strategies that affect how much tile you use.
Floor tile vs backsplash
The math is identical — enter wall length and height for backsplash projects. Waste runs higher on walls because of outlets, switches, and window sills.
For full floor prep and thinset estimates, start with how to prep for tile floor. For product selection, see how to choose floor tile.
Related guides
Frequently asked questions
How do I find sq ft per tile box?
Check the box label. Multiply tile size × pieces per box ÷ 144, or use the printed coverage area.
Does this work for backsplash tile?
Yes. Enter backsplash length and height as your room dimensions for wall tile projects.
Related calculators
Flooring Box Calculator · https://flooringboxcalculator.com/how-many-tiles-do-i-need/