Tile & Flooring Calculator — How Many Tiles Do I Need?

Enter your floor area and tile size to instantly see exactly how many tiles — and boxes — you need to buy, with a wastage allowance built in so you never run short mid-install.

The Tile Calculation Formula, Explained

Every tiling estimate starts from one question: how much area does one tile cover, and how many of them fit in the room? The answer is a two-part division followed by a rounding step:

Step	Formula
Area of one tile	Tile area = Tile length × Tile width
Exact tile count	Tiles = Room area ÷ Tile area
Add wastage	Buy = Round up (Tiles × (1 + Wastage ÷ 100))
Boxes to buy	Boxes = Round up (Buy ÷ Tiles per box)

For a square tile, length and width are the same, so the tile area is simply the side squared. The calculator handles inches, centimeters, feet, and meters — it converts the tile dimension into the same unit system as your room before dividing, so you never mix up a 12-inch tile with a 12-centimeter one.

Step-by-Step Example: Tiling a 10 × 12 ft Room

Let's tile a 10 × 12 ft bathroom floor with 12 × 12 inch porcelain tiles, using the calculator's default 10% wastage and 10 tiles per box.

Calculate the floor area: 10 × 12 = 120 sq ft.
Calculate the tile area: a 12 × 12 in tile is 1 ft × 1 ft = 1 sq ft.
Divide: 120 ÷ 1 = 120 tiles, exactly.
Add wastage: 120 × 1.10 = 132 tiles.
Round up and box: 132 ÷ 10 = 13.2, so 14 boxes.

Re-enter those numbers above and the widget reproduces every step instantly — and recalculates live if you change any dimension or the wastage slider.

Reference Tables

Common Room Sizes → 12×12 in Tiles (10% Wastage, 10 per Box)

Room	Floor Area	Tiles to Buy	Boxes
5 × 7 ft (small bath)	35 sq ft	39	4
6 × 8 ft (bathroom)	48 sq ft	53	6
10 × 12 ft (bedroom)	120 sq ft	132	14
12 × 14 ft (kitchen)	168 sq ft	185	19
14 × 16 ft (master bedroom)	224 sq ft	247	25

Common Tile Sizes → Area per Tile

Tile Size	Sq Ft per Tile
12 × 12 in	1.00
12 × 24 in	2.00
24 × 24 in	4.00
60 × 60 cm	0.36 m²
30 × 60 cm	0.18 m²

Troubleshooting & Practical Tips

Measure Twice, Including the Odd Spots

A room is rarely a perfect rectangle. Doorways, alcoves, closets, and bay windows all add floor that the "length × width" figure misses. Measure each section separately and add the areas together before entering the total — a 2 × 3 ft alcove is 6 extra sq ft, which is half a dozen 12-inch tiles you'd otherwise be short on.

Layouts That Waste More

Straight-lay (grid) floors are the most economical at 10% wastage. A running-bond (offset) layout uses slightly more because the staggered pattern cuts are shorter. Diagonal, herringbone, and chevron layouts push wastage to 15–20% because nearly every edge tile is an angled cut. If your room has curved walls or many inside corners, budget the same way — the calculator's slider goes to 30% for a reason.

Large Format, Bigger Risk

24 × 24 in and larger tiles are beautiful but unforgiving: a single miscut wastes a whole square foot or more, and chipped corners are harder to hide. Order 15% extra for large-format tile, and always keep the partial box afterward — matching a replacement tile later is nearly impossible once a batch sells out.

Common Mistakes to Avoid

Mixing units — a 12 cm tile is about 4.7 in, not 12 in. Keep room and tile in the same system.
Forgetting doorways, alcoves, and the area under cabinets you plan to tile.
Skipping the wastage allowance entirely, then running out after a single cracked tile.
Rounding the box count down because 13.2 "looks close to 13" — 13 boxes leaves you short.
Assuming all tiles in a box are identical — natural stone varies in shade batch to batch, so buy it all at once.

Frequently Asked Questions

How many 12×12 inch tiles do I need for a 10×12 ft room?

A 10×12 ft room is 120 sq ft, and each 12×12 in tile covers exactly 1 sq ft. Before wastage that's 120 tiles. With the calculator's default 10% allowance you'd buy 132 tiles, and at 10 tiles per box that's 14 boxes. If the room has a doorway, alcove, or closet, measure those separately and add them to the area.

Why do I need a wastage allowance when the math is exact?

Because a real floor is never a perfect grid of whole tiles. Every edge, corner, and doorway needs a cut tile, and cutting carries a risk of breakage — especially with large-format or natural-stone tiles. A 10% allowance covers a straightforward straight-lay floor; diagonal layouts, herringbone, and rooms with many angles typically need 15% or more, which is why the calculator's slider goes up to 30%.

Should I round up to whole boxes or buy tiles individually?

Most tiles are sold in boxes, so you can't buy 132.4 tiles — you buy the box count that contains at least that many. Our calculator rounds both the tile count and the box count up for you. If your total comes to 14.1 boxes, buying 15 is the safe choice: a partial extra box is cheap insurance against a damaged tile arriving, or needing one spare later for a repair.

How much does the tile size change my estimate?

The tile count scales with area, not with tile size — a 100 sq ft floor needs 100 sq ft of tile regardless of whether the tiles are 12×12 in or 24×24 in. What changes with size is the wastage you should allow: large-format tiles (24 in and up) waste more because cuts are bigger and harder to reuse, so bump the slider toward 15–20%.

Do grout lines affect how many tiles I need?

Not meaningfully. Grout lines are typically 1/8 to 1/4 inch wide, which is a rounding error over the area of a room — you can't buy a fraction of a tile to account for them. Just set your tile size to the nominal size printed on the box and use the wastage slider for the gap, cuts, and breakage.

Is this calculator suitable for vinyl plank or laminate flooring?

Yes — the same area ÷ tile-area math applies to any plank or tile you buy by the box: vinyl plank, laminate, wood-look tile, and carpet tile. For narrow planks the wastage percentage behaves slightly differently (planks waste less because they're cut to length), so 10% is generous; for diagonal plank installation keep the 15%+ setting.