Calculate how many tiles you need for your project, accounting for waste and trim.
Room Size
sq ft
Tile Size
in W
in H
%
Tiles Needed
1tiles
This includes 0 waste tiles (10% allowance) for cuts, breakage, and future repairs.
Room Area120 sq ft
Tile Area144 sq in
Tiles Without Waste1
Waste Tiles0
Most professionals recommend a 10–15% waste allowance for standard installations. Increase waste to 20% for diagonal patterns, large tiles, or difficult layouts. Always buy extra tiles for future repairs.
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What is the Tile Calculator?
A tile calculator determines how many tiles are required to cover a given area, accounting for the size of individual tiles and a waste percentage (typically 10–15%). For example, a 120 sq ft room with 12×12 inch tiles requires approximately 120 tiles before waste; with 10% waste allowance, you'd order 132 tiles. This prevents running short mid-project.
How it works
Enter your room area in square feet (or length and width separately). Specify tile dimensions in inches (width and height). Enter your desired waste allowance percentage (default 10%). The calculator divides total area by tile area, multiplies by waste factor, and rounds up to the nearest whole tile.
First, convert room area to square inches (multiply sq ft by 144). Divide by tile area in square inches. Multiply by (1 + waste percentage). Round up because you cannot order a partial tile. For a 120 sq ft room (17,280 sq in), 12×12 tiles (144 sq in each), with 10% waste: (17,280 ÷ 144) × 1.10 = 120 × 1.10 = 132 tiles.
Measure your room or space in feet (length × width) or use the total square footage
Measure or select your tile size in inches (width and height)
Decide on a waste allowance percentage (10% is standard; use 15–20% for complex patterns)
Enter all values into the calculator
Review the total tiles needed and breakdown of waste tiles
Order slightly more than the total (at least 5% extra for future repairs)
Benefits
Precise quantity — avoid ordering too few tiles and running short mid-project
Waste factored in — automatically accounts for cuts, breakage, and future touch-ups
Two input modes — enter total area or length × width for flexibility
Instant breakdown — see tiles without waste, waste quantity, and final total separately
Supports all tile sizes — works with standard (12×12), large (24×24), mosaic, and custom sizes
Tips & common mistakes
Common mistakes
Forgetting to add waste — ordering exact quantity for area leaves no margin for cuts and breakage
Using wrong unit — mixing feet and inches or confusing sq ft with linear feet
Not measuring accurately — a 2–3 foot discrepancy can mean 10+ extra tiles needed
Ignoring pattern complexity — diagonal, herringbone, or accent patterns require 20%+ waste, not 10%
Tips
For rectangular rooms with simple layouts, 10% waste is sufficient. Increase to 15–20% for diagonal patterns.
Always keep extra tiles for future repairs. Colors and batches vary; replacement tiles may not match perfectly later.
Large-format tiles (18×18, 24×24) require more waste due to larger cuts. Mosaics need less waste per area.
Round up—never down. If the calculator says 131.2, order 132. If the supplier offers partial cases, know your case count.
Frequently asked questions
What waste percentage should I use?
For simple rectangular layouts, 10% is standard. Increase to 15% for average installations, and 20% for diagonal patterns, large tiles, or complex layouts like L-shaped rooms.
Do I measure from the center of wall to wall?
No. Measure the clear floor or wall surface where tiles will be laid. Do not include baseboards or fixtures. Measure to the point where the tile edge will land, not the wall surface itself.
What if my room is L-shaped or irregular?
Divide it into rectangles, calculate area for each section separately, add them together, then use the total area in the calculator. Increase waste to 15–20% to account for extra cuts.
Do I need to account for grout lines?
No. Grout lines are negligible—typically 3–5mm. The tile count is based on the physical tile size, not accounting for grout spacing.
What if I order too many tiles?
Most suppliers accept returns within 30 days for unused, unopened boxes. Keep your receipt and packaging. It is better to order extra than to run short mid-project.
How do I calculate mixed tile sizes (e.g. main tiles + trim pieces)?
Calculate the main tiles separately, then add trim pieces by linear foot or individual count. The calculator works best for uniform tile size across the main area.