Construction & DIY
Tile Calculator
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How to use it
Using the tile calculator
- 01
Measure the area
Multiply length by width of each space and add them together for odd-shaped rooms.
- 02
Enter tile dimensions
Use the face dimensions printed on the box; 12×24 plank and 2×2 mosaic behave very differently.
- 03
Set waste and buy
Keep 10% for straight layouts, raise it for diagonals. Round the final count up to full boxes.
Good to know
Why waste is not optional
Every field cuts tiles at edges, and every job loses a few to snap mistakes. Running one tile short mid-project means a second shipment from a different dye lot; visibly off-color next to the original. The waste allowance is insurance against both.
Big tiles, big surprises
Large-format planks look fast but generate proportionally larger offcuts in small rooms; mosaics come mesh-backed so their sheet size, not individual tile size, drives cutting. Measure twice for patterned layouts where matching shifts everything.
Keep spares
Styles get discontinued constantly. Stashing one box from every job gives you free repairs for cracked tiles years later; arguably the cheapest insurance in home improvement.
How it's calculated
The math behind this calculator
Tiles = ⌈ Area × (1 + waste%) ÷ (Tile L(in) × Tile W(in) / 144) ⌉Each tile covers its length times width divided by 144 (square inches per square foot). The area inflated by the waste percentage is divided by that per-tile coverage and rounded up to whole tiles; boxes follow as boxes-of-ten.
Assumptions & limitations
- Flat rectangular installation area.
- Waste covers cuts around edges, breakage and a few spares.
- Diagonal or herringbone layouts need closer to 15–20% waste than 10%.
Worked example
Tiling 100 sq ft with 12"×12" tiles and 10% waste: 110 effective sq ft ÷ 1 sq ft per tile = exactly 110 tiles, or 11 boxes of ten.
FAQ
Frequently asked questions
- How much extra tile should I buy?
- 10% suits straight layouts in rectangular rooms; 15–20% for diagonal, herringbone, or many corners and jogs.
- Do grout lines change the count?
- Slightly; grout joints usually offset tile size, but the standard practice of rounding up absorbs the difference.
- Are tiles sold individually?
- Mostly by the box. Use the boxes-of-ten row as a starting point, then confirm actual pieces-per-box on the product listing.
- Does underlayment or thinset matter here?
- Not for tile count; but thinset and grout quantities do scale with tile size and joint width, so budget them separately.
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