Free calculator
Tile Calculator: How Many Tiles Do I Need?
Tiles are sold by the box, priced per tile or per square foot, and your room is measured in feet and inches. Enter your floor area and tile size for a tile count with waste allowance plus exactly how many boxes to buy. No sign-up; the math runs entirely in your browser.
By HowMuchBuild Editorial TeamCalculation reviewedUpdated October 2026
ft
in
ft
in
Cuts, breakage, and a few spares for future repairs.
printed on the box or product listing
Estimated cost
What will it cost?
Enter your local store prices — prices vary by region.
Tile (per tile)
66 tiles
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Tile (per box)
9 boxes
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Estimate — prices vary by store and region. Check your local store for current pricing.
You need
66tiles
120 sq ft · 12″ × 24″ · 10% waste included
Buy 9 boxes (8 tiles per box, rounded up)
120
sq ft · floor area
66
tiles · with waste
9
boxes · to buy
How we calculated it
- Floor area = 10 ft × 12 ft = 120 sq ft
- Tile size = 12″ × 24″ = 288 sq in ÷ 144 = 2 sq ft per tile
- Tiles = 120 ÷ 2 = 60 × 1.10 (10% waste) → round up = 66 tiles
- Boxes = 66 tiles ÷ 8 per box → round up = 9 boxes
Estimates for planning. Keep a few spare tiles from the same dye lot for future repairs — shade varies between batches. Measure each room separately; L-shaped rooms need the area split into rectangles.
Worked example: 10×12 ft room, 12×24″ tile
Full arithmetic, step by step:
- Floor area: 10 ft × 12 ft = 120 sq ft
- Tile area: 12 × 24 = 288 sq in ÷ 144 = 2 sq ft per tile
- Exact tiles: 120 ÷ 2 = 60 tiles
- With 10% waste: 60 × 1.10 = 66 → 66 tiles
- Boxes: 66 ÷ 8 per box = 8.25 → 9 boxes
Chart: tiles per 100 sq ft
Tiles needed per 100 sq ft at common sizes, with 10% waste included (exact arithmetic, rounded up):
| Tile size | Sq ft per tile | Tiles per 100 sq ft |
|---|---|---|
| 12″ × 12″ | 1 | 110 |
| 12″ × 24″ | 2 | 55 |
| 18″ × 18″ | 2.25 | 49 |
| 24″ × 24″ | 4 | 28 |
The formulas
Floor area
A = L × W — in feet. Split L-shaped rooms into rectangles and add the areas.
Tile area
Tile sq ft = (length in inches × width in inches) ÷ 144 — exact, since one square foot is 144 square inches.
Tiles and boxes
Tiles = ⌈ A ÷ tile sq ft × (1 + waste) ⌉, then Boxes = ⌈ tiles ÷ tiles per box ⌉. Both always rounded up — partial tiles and boxes don't exist at the register.
Frequently asked questions
How many tiles do I need for a 10×12 ft room?
120 sq ft. With 12×24″ tiles (2 sq ft each): 120 ÷ 2 = 60 tiles × 1.10 (10% waste) = 66 tiles. At 8 tiles per box, that's 66 ÷ 8 = 8.25 → 9 boxes.
Should I use 10% or 15% waste?
10% is standard for a straight lay in a rectangular room (guidance). Choose 15% for diagonal layouts, large-format tile, or rooms with many corners and cuts — every cut risks a broken tile.
How do I measure an L-shaped room?
Split it into rectangles, calculate each area separately, and add them (guidance). Never guess the area of an irregular room — measure each rectangle's length and width, then sum the square footage before entering it here.
Why buy extra tiles beyond the waste allowance?
For future repairs (guidance). Tile dye lots vary in shade between production runs, so a cracked tile replaced a year later may not match. The waste allowance usually leaves spares — keep them, labeled, from the same lot.
How many tiles come in a box?
It varies by tile size and manufacturer — check the box or product listing and enter it in the calculator. Larger tiles mean fewer per box; the calculator converts your tile count into boxes automatically.
Does grout line width change the tile count?
Barely (guidance). Grout joints are typically 1/8″–1/4″ and their area is absorbed by the waste allowance. Don't shrink your order to account for grout — the 10–15% allowance already covers it.
Keep estimating