How Many Tiles Do I Need?

Enter your room and tile dimensions to find out exactly how many tiles to buy, including waste allowance for cuts and breakage.

How to Calculate Tiles Needed

To calculate tile quantity, divide the total area (in sq ft) by the area of each tile. Always add a waste factor of 10–20% for cuts, breakage, and future repairs. For diagonal or herringbone patterns, use 15–20% waste.

For example, covering a 10×8 ft floor (80 sq ft) with 12×12 inch tiles at 10% waste requires approximately 89 tiles.

How Much Waste Factor Should I Use?

Use 10% for straight lay patterns in simple rectangular rooms. Use 15% for diagonal layouts or rooms with multiple angles. Use 20% for herringbone, chevron, or other complex patterns where more cuts are required.

Tile Quantity Quick Reference

Room Size	12×12" Tiles (10% waste)	18×18" Tiles (10% waste)
50 sq ft bathroom	61 tiles	28 tiles
100 sq ft bathroom	122 tiles	55 tiles
150 sq ft kitchen	183 tiles	82 tiles
200 sq ft space	243 tiles	109 tiles

Always buy from the same production batch (dye lot) — tiles from different batches can have subtle color and size variations that show up clearly on a finished floor. Check every box for the lot number before purchasing and before starting installation.

Choosing the Right Tile Size for Your Space

Tile size has a significant visual impact on room proportions. Large-format tiles (18×18 in or bigger) make small rooms feel larger by reducing the number of grout lines. Small mosaic tiles (2×2 in or smaller) add texture and work well in showers and backsplashes but require more time to install and more grout to maintain.

For floor tile, the general rule is to use tiles no larger than one-third the width of the narrowest wall in the room. A 5-ft wide bathroom can use up to 18×18 in tiles comfortably. A 10-ft wide kitchen can handle 24×24 in large-format tiles without looking out of scale.

Tile Material Cost Comparison

Tile Type	Material Cost (per sq ft)	Labor Cost (per sq ft)	Best For
Ceramic	$1–$5	$4–$8	Walls, low-traffic floors
Porcelain	$3–$10	$5–$10	High-traffic floors, wet areas
Natural stone (travertine)	$5–$15	$7–$15	Upscale bathrooms, entry
Marble	$10–$30	$10–$20	Master baths, accent walls
Subway tile (ceramic)	$2–$6	$5–$10	Kitchen backsplash, shower walls
Glass mosaic	$8–$25	$10–$20	Backsplash accents

Tile Installation Tips

• Start from the center — Find the center of the room and work outward so cut tiles are equal on opposite walls
• Check for lippage — Use a straightedge to confirm tiles are flush; lippage (tiles not level with each other) is the most common installation complaint
• Let mortar cure before grouting — 24–48 hours minimum before applying grout
• Seal grout after curing — Unsealed grout stains easily and is difficult to clean; seal within 72 hours of grouting
• Use the right trowel notch size — 3/16 in V-notch for wall tile, 1/4 in square-notch for floor tile, 1/2 in for large-format tile

Common Tile Ordering Mistakes

• Rounding down instead of up — Always round the tile count up to the next whole tile, then up again to the next full box. "Close enough" math is the #1 reason people end up short mid-install.
• Forgetting niches, curbs, and steps — Shower niches, curbs, and step edges eat noticeably more tile than a flat area calculation suggests, since almost every piece around them requires a cut. Add these as separate line items, not an afterthought.
• Using straight-lay waste for a pattern layout — Herringbone, chevron, and diagonal layouts create far more offcuts than a straight lay. Using 10% waste for a pattern job can leave you a full box short.
• Skipping trim and bullnose pieces — Exposed edges (window sills, half-walls, outside corners) usually need bullnose or edge trim, which is ordered separately from field tile and easy to miss on a first takeoff.
• Not reserving repair stock — Buy at least one extra box beyond your waste-adjusted total and store it. Dye lots change between production runs, so matching tile years later for a repair is often impossible.

Frequently Asked Questions

How many tiles do I need for a 100 sq ft floor?

For a 12x12 inch tile (1 sq ft each) with 10% waste, plan on about 110 tiles for 100 sq ft. Smaller tiles need proportionally more pieces.

How much extra tile should I buy for a diagonal layout?

Add 15% waste for a diagonal layout, compared to 10% for a standard straight lay, since diagonal cuts create more unusable offcuts.

Should I buy extra tile for future repairs?

Yes, buy at least one extra box beyond your waste-adjusted total — matching tile from the same production lot years later is often impossible.

Does tile size affect how much I need to order?

Larger format tiles generally waste less material proportionally since fewer cuts are needed, though they cost more per tile.