Calculation details
Planning estimate only. Verify dimensions, waste, coverage, product specifications, and local requirements before purchasing materials.
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What does this calculator estimate?
A tile calculator estimates how many tiles and boxes you need for a floor or wall. Enter the surface dimensions, tile size, waste percentage, and tiles per box to get the quantity.
- Tile area in sq ft = (L × W in inches) ÷ 144
- Tiles = ceil(surface × (1 + waste) ÷ tile area)
- Boxes = ceil(tiles ÷ tiles per box)
How tile quantity is estimated
Tile is measured by the square foot. The surface area is divided by the area of one tile to get the count, then multiplied by a waste factor for cuts and breakage, and finally rounded up to whole boxes.
Limitations to watch for
The estimate assumes one consistent tile size. Diagonal layouts, borders, and rooms with many edges waste much more. Grout lines don't materially change the count. Boxes per tile and exact tile sizes vary by product — confirm the actual dimensions.
How to use it in practice
Measure the surface length and width (or split an irregular room into rectangles). Add 10–15% waste — more for diagonal layouts. Convert tile size to square feet before dividing. Round up to full boxes.
['Enter the surface length and width.', 'Enter the tile length and width in inches.', 'Enter waste % and tiles per box; the tool computes tiles and boxes.']
How this calculator works
Formula
Surface area = area length × area width. Tile area = tile length × tile width ÷ 144 (sq ft). Tiles needed = ceil(surface area × (1 + waste%) ÷ tile area). Boxes = ceil(tiles needed ÷ tiles per box).
Worked example
A 10 × 12 ft floor (120 sq ft) with 12×12 in tiles and 10% waste: needed = ceil(120 × 1.10 ÷ 1) = 132 tiles. At 10 tiles per box: ceil(132 ÷ 10) = 14 boxes.
Assumptions to verify
- The surface is rectangular.
- Tiles are square or rectangular with dimensions entered in inches.
- Waste covers cuts, breakage, and future repairs.
Frequently asked questions
How do I calculate how many tiles I need?
Divide the surface area (sq ft) by the area of one tile (sq ft), multiply by the waste factor, and round up. For 120 sq ft with 1 sq ft tiles, that's about 132 tiles with 10% waste.
How do I convert tile size to square feet?
Multiply length × width in inches, then divide by 144. A 12×12 in tile = 1 sq ft; a 6×24 in tile = 1 sq ft too.
How much extra tile should I buy?
10–15% is standard for straight layouts. Diagonal patterns and rooms with many cuts can need 20% or more. Extra tile is also insurance for future repairs.
Do grout lines affect the count?
Negligibly — grout lines are small fractions of an inch and don't change whole-tile counts materially.
Why round up to whole boxes?
Tile is sold by the box. Buying whole boxes ensures you have matching dye lots for the whole job.
What about wall vs floor tile?
The math is the same. Just measure the wall surface (width × height, minus openings) the same way.
What if my room isn't rectangular?
Split it into rectangles, calculate each, and add them. The tool assumes one rectangle per calculation.
Cite this tool
BoringToolsKit. “Tile Calculator.” boringtoolskit.com/tile-calculator/ (reviewed 2026-08-25). Free to reference in articles, syllabi, and answer posts with a link.
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