Tile Calculator — Square Feet, Tiles & Waste

How to use this tile calculator

Enter the total square footage of the area you're tiling, the width and length of each tile in inches, and the waste factor (10% is standard). The calculator returns total tiles needed including waste, exact tiles needed, estimated boxes, and the area per tile.

For walls and backsplashes, measure the height × width of each surface and add them together. Subtract large openings (over 10 sq ft) like windows, but ignore outlets and small penetrations — you'll need tiles to cut around these anyway.

For L-shaped rooms, break into rectangles and sum. The waste factor accounts for cutting losses, breakage, and future repairs.

How much waste do I add?

The right waste factor depends on your layout complexity:

• Straight lay, simple rectangular room, 12" tiles: 10%
• Straight lay, complex shape or small tiles (6" or smaller): 12–15%
• Diagonal / 45° layout: 15%
• Herringbone pattern: 15–20%
• Hexagonal or mosaic: 15%
• First-time DIY installer: add 5% extra to any above
• Discontinued or hard-to-find tile: add 5% for future repairs

15% is the universal safe default if you're uncertain. Most professional installers budget 10% but have the skill to minimize cuts. Having leftover tile for repairs is far cheaper than hunting down a replacement box five years later.

Tile sizing: what works where

Small tiles (subway 3x6, mosaic, penny rounds):

• Great for walls, backsplashes, shower floors (more grout = better grip)
• More cuts, more grout, longer install time
• Forgiving with uneven surfaces

Medium tiles (6x6, 8x8):

• Standard for kitchen and bathroom floors
• Classic look, middle-ground install difficulty
• Work in most rooms

Large tiles (12x12 up to 12x24):

• Modern look, fewer grout lines, easier to clean
• Less forgiving — requires very flat substrate
• Floor-only for most homes; needs skilled install

Extra-large / plank (24x48, 12x48):

• High-end residential and commercial
• Demanding substrate prep (1/8" flatness requirement)
• Professional install recommended

Small bathrooms often look larger with bigger floor tiles. Open rooms handle any size. For backsplashes, subway and mosaic tiles dominate for good reason — they're forgiving and timeless.

Box counts and ordering

Tile is sold by the box, not the individual tile. Box coverage varies wildly:

• 12x12 floor tile: typically 15 sq ft per box
• 6x24 plank tile: 10–12 sq ft per box
• 3x6 subway tile: 10 sq ft per box
• Mosaic sheets: 8–10 sq ft per box

Always round UP to the nearest full box. You can't buy half a box, and partial boxes later (even from the same run) often show lot variations in color.

Key rule: order all your tile from the same lot number. Different production runs have subtle color differences. Big box stores usually let you specify this, but confirm when ordering.

The cost breakdown

Tile prices in 2026:

• Budget ceramic (glazed): $1–$3 per sq ft
• Mid-grade porcelain: $3–$8 per sq ft
• Natural stone (travertine, marble): $5–$15 per sq ft
• High-end porcelain / large format: $8–$20 per sq ft
• Designer / imported: $15–$50+ per sq ft

Installation costs (professional):

• Floor tile: $5–$12 per sq ft labor
• Wall tile / backsplash: $7–$15 per sq ft labor
• Complex patterns: +30–50% labor

Materials beyond tile:

• Thinset mortar: ~$0.50 per sq ft
• Grout: ~$0.25 per sq ft
• Underlayment / backer board: $1–$2 per sq ft

For a 100 sq ft bathroom floor with mid-grade 12x12 tile, budget around $800–$1,500 DIY or $1,500–$2,800 professionally installed.

Pro tips before you tile

• Buy one extra box beyond calculator recommendations. Stored in a dry place, it's your repair insurance for 10+ years.
• Lay out the first few rows dry before applying thinset. Centerlines, cuts at walls, and pattern alignment are easier to see without adhesive.
• Plan cuts to show full tiles in the most visible area. Hidden corners get the cut pieces.
• Use tile spacers religiously. Consistent grout lines are what separate pro from amateur work.
• Don't walk on fresh tile for 24 hours. Thinset needs time to set; too-early foot traffic creates invisible hollow spots.
• Seal natural stone before AND after grouting. Unsealed stone absorbs grout permanently.