How do I calculate how many tiles I need?

Multiply the room's length by its width to get square footage. Divide that by the area of one tile (in square feet) and add a 10% waste buffer. For example: 120 sq ft room ÷ (12×12 tile = 1 sq ft) × 1.10 = 132 tiles, then round up to full boxes.

How many 12x12 tiles do I need for 100 square feet?

A 12×12 tile covers exactly 1 square foot. For 100 square feet with a standard 10% waste buffer, you need 110 tiles. If your tiles come in boxes of 10, that's 11 boxes.

How many tiles do I need for a 10x10 bathroom?

A 10×10 ft bathroom is 100 square feet. For 12×12 tiles with 10% waste: 110 tiles (11 boxes of 10). For 12×24 tiles (0.667 sq ft each) with 10% waste: about 165 tiles. Remember that floor tiles and wall tiles are calculated separately.

Should I buy extra tiles beyond the calculated amount?

Yes — always buy at least 10% extra, and keep a few leftover tiles stored with your purchase receipt. Tiles are often discontinued and getting an exact dye-lot match years later when a tile cracks is nearly impossible. For diagonal or herringbone layouts, budget 15–20% extra instead of 10%.

Do I need to order all my tiles at once to ensure matching dye lots?

Yes, this is critical. Tile manufacturers produce batches with slight color and texture variations between lots. Order all tiles for a project in one purchase, from the same lot number (printed on the box). If you run short later, the replacement tiles may not match — even if the product code is identical.

How Many Tiles Do I Need?

Last updated: June 2026

Quick answer: For a straight-lay installation, divide your room's square footage by the tile's square footage and multiply by 1.10 (10% waste). A 100 sq ft room with 12×12" tiles needs 110 tiles. For a diagonal or herringbone layout, use 1.15–1.20 instead.

The tile count question sounds simple — but there are four things that trip up almost every DIYer: waste factor, tile format vs. coverage, box sizing, and dye-lot matching. Getting any one of these wrong means a second trip to the store, or worse, running out mid-project with no matching tile in stock.

Below you'll find tile count tables for the most common room sizes and tile formats, plus a calculator for your exact dimensions.

🟦 Calculate your exact tile count Open full calculator ↗

Tile count by room size — 12×12" tiles

12×12" tiles cover exactly 1 square foot each. These numbers include a 10% waste buffer for straight-lay installation.

Room size	Area (sq ft)	Net tiles needed	With 10% waste	Boxes (10 tiles/box)
6×6 ft (small bath)	36	36	40	4 boxes
8×8 ft	64	64	71	8 boxes
10×10 ft	100	100	110	11 boxes common
12×12 ft	144	144	159	16 boxes
10×15 ft (kitchen)	150	150	165	17 boxes
12×16 ft	192	192	212	22 boxes
15×20 ft (living room)	300	300	330	33 boxes
20×25 ft (large living)	500	500	550	55 boxes

Tile count by format — 100 sq ft room

Larger tiles cover more area per tile but waste more at edges. Smaller tiles have more grout lines and more flexibility around obstacles.

Tile size	Sq ft per tile	Net tiles (100 sq ft)	With 10% waste	Notes
4×4"	0.111	900	990	Backsplash, accent walls
6×6"	0.25	400	440	Small bathrooms
6×12"	0.5	200	220	Subway tile walls, shower surrounds
12×12"	1.0	100	110	Most popular floor tile popular
12×24"	2.0	50	55	Modern kitchens, larger spaces
18×18"	2.25	45	50	Foyers, open plans
24×24"	4.0	25	28	Large format, spacious feel

How pattern affects tile count

The layout pattern dramatically changes how many tiles you need. Diagonal and herringbone patterns require more cuts — which means more waste — especially at the room's perimeter.

Pattern	Waste factor	Tiles for 100 sq ft (12×12)	Why the extra waste
Straight lay	10%	110 tiles	Edge and corner cuts only
Brick / offset	10%	110 tiles	Similar to straight but slightly more edge cuts
Diagonal 45°	15%	115 tiles	Every perimeter tile is cut at 45° — large offcuts
Herringbone	20%	120 tiles	Tiles cut at multiple angles; tight fit requires more trial and error

Tips for ordering the right amount

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Match dye lots

Check the lot number on every box before purchase. Tiles from different lots can vary in shade — visible once installed. Order all tiles in one trip from the same lot.

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Keep 3–5 spares

Store leftover tiles after installation. If a tile ever cracks or chips, you'll need an exact match — same product code, same lot. Matching years later is often impossible.

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Measure twice

Measure each room at its widest point. Rooms are rarely perfect rectangles — bay windows, alcoves, and closets all affect your count. Add rooms separately for accuracy.

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Don't deduct openings

Resist the urge to subtract doors and cabinets from your tile count. Those cut tiles still get wasted in cutting. Only deduct large permanent islands or fixed built-ins.

Frequently asked questions

Measure the room's length × width to get square footage. Divide by the tile's square footage (tile width in inches × tile length in inches ÷ 144). Then multiply by 1.10 for a 10% waste buffer and round up. Finally, divide by tiles per box and round up to full boxes.

A 12×12" tile covers exactly 1 sq ft. For 100 sq ft with 10% waste: 110 tiles. If your tiles come in boxes of 10, that's 11 boxes. For a diagonal layout, use 115 tiles (12 boxes). Always buy whole boxes — partial boxes often can't be returned once opened.

A 10×10 ft floor is 100 sq ft. With 10% waste: 110 tiles at 12×12", or 55 tiles at 12×24". Don't forget to calculate the walls separately if you're tiling those too — wall tiles are usually a different product. A full 10×10 bathroom tile job (floor + 4 walls to 6 ft) can require 400–600 sq ft of tile total.

Yes. Buy at least 10% extra and store the leftovers. If a tile cracks in 3 years and the product has been discontinued — which happens often — you'll have no way to repair it without a visible mismatch. Most experienced tilers buy 15% extra as a rule, especially for custom or imported tiles.

Yes — this is one of the most common tiling mistakes. Tiles are manufactured in batches. Even identical products from different batches can vary in color, texture, or size by a fraction of a millimeter. Order everything at once, check that all boxes share the same lot number, and open one box from each lot to compare before installation.

Get your exact tile count

Enter your room dimensions, pick your tile size and layout pattern — get tiles, boxes, grout, and a complete supply list.

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