Tile Calculator

How to calculate how many tiles you need

Every tile estimate comes down to three numbers: the area you are covering, the size of one tile, and a waste allowance for cuts and breakage. Find the area in square feet, divide by the area of a single tile to get the raw count, then add a waste percentage so you finish the job with tile to spare. The calculator above does all of this for any tile size and converts the result into boxes and an estimated cost.

tiles = area (sq ft) ÷ (tile width × tile height ÷ 144) × (1 + waste %)

The ÷ 144 converts a tile measured in inches into square feet (there are 144 square inches in a square foot). For oddly shaped rooms, measure each rectangle separately and add the areas together before you divide.

Step by step

• 1. Measure the area. Multiply length × width in feet for a floor, or perimeter × height for a wall. For a small backsplash measured in inches, multiply length × width and divide by 144.
• 2. Find the area of one tile. Tile width × height in inches, divided by 144. A 12 × 12 in tile is 1.0 sq ft; a 6 × 6 in tile is 0.25 sq ft.
• 3. Divide and round up. Area ÷ tile area gives the bare count. Always round up to a whole tile.
• 4. Add waste. Multiply by 1.10 for a standard straight layout, more for diagonal or patterned work (see the table below).

Worked example

Say you are tiling a bathroom floor that is 8 ft × 10 ft = 80 sq ft with 12 × 12 in tiles in a straight layout.

• Area of one tile: 12 × 12 ÷ 144 = 1.0 sq ft
• Raw count: 80 ÷ 1.0 = 80 tiles
• Add 10% waste: 80 × 1.10 = 88 tiles
• At ~15 sq ft per box, that is 88 ÷ 15 ≈ 6 boxes

Switch to a diagonal layout and the waste jumps to 15%, giving 80 × 1.15 = 92 tiles — proof that the pattern, not just the room size, drives how much you buy.

Tiles per 100 square feet by size

A quick reference for the most common tile sizes. To get your own count, multiply the per-100-sq-ft figure by your area in hundreds of square feet, then add waste.

Figures exclude grout joints, which slightly reduce the tile count on tight, large-format layouts.

How much extra tile to buy: waste factor by pattern

The layout decides how many cuts you make, and cuts are where tile gets wasted. A simple grid wastes little; a herringbone or diagonal pattern wastes far more because almost every perimeter tile is cut on an angle. Natural stone also needs a bigger cushion because more pieces arrive cracked or with shade variation you will cull. These ranges line up with what tile suppliers and installers recommend.

Buy all your tile from the same batch (dye lot) in one order — shade can drift between production runs, and a box bought weeks later may not match. The extra tile also becomes your attic stock for future repairs, since discontinued lines are impossible to match.

Don't forget grout, thinset and backer board

The tile count is only part of the shopping list. Three materials go under and between the tiles:

• Thinset mortar bonds tile to the substrate. Coverage depends on trowel size: with a 1/4 in square-notch trowel a 50 lb bag covers roughly 50–55 sq ft, but a 1/2 in trowel for large-format tile covers only about 30–35 sq ft because the deeper notches lay down more mortar (per industry coverage guides such as The Tile Shop). Back-buttering large tiles uses 15–20% more.
• Grout fills the joints. Use unsanded grout for joints up to 1/8 in and sanded grout for wider joints — the wrong one cracks or won't pack. Deep or rounded tiles use 2–4× more grout than flat tiles.
• Backer board (cement board) gives a stable, water-resistant base on floors and wet walls. It is sold in 3 × 5 ft sheets in 1/4 in and 1/2 in thicknesses.

Never butt tiles tight against each other — even rectified tile needs a small joint so the surface can move without cracking.

Tile cost: material and installed (2026 estimates)

Tile price varies widely by material, and installation usually costs more than the tile itself. The ranges below are typical 2026 US figures for budgeting; your local quote will vary by region, tile grade and job complexity.

Add-ons that raise the bill: labor runs about $5–$22 per sq ft (most flat ceramic/porcelain jobs land $7–$15); complex patterns like herringbone or diagonal add roughly 15–25% to labor; subfloor leveling adds $2–$5 per sq ft; and tearing out old tile adds about $3–$7 per sq ft including disposal. To price the whole room rather than just the tile, use the flooring calculator for box counts on plank products.

Cost figures are estimates and vary by region and over time; get a local quote for 2026 pricing.

Common mistakes

• Buying exactly what you measured. Skipping waste means a second trip — and possibly a mismatched dye lot — when you run short on the last row.
• Forgetting to subtract big openings but not cuts. Subtract large fixtures (a tub, a vanity footprint) from the area, but still keep full waste for the cuts around them.
• Mixing grout types. Sanded grout in a 1/16 in joint leaves voids; unsanded grout in a 3/8 in joint cracks out.
• Ignoring the substrate. No backer board or uneven subfloor leads to cracked tile and lippage no amount of extra tile fixes.
• Pricing tile but not the rest. Thinset, grout, spacers, trim and backer board often add 20–30% to the material bill.

When to hire a pro

A straight-lay floor or a simple backsplash in a square room is a realistic weekend DIY job if you can rent a wet saw and work patiently. Lean toward a pro tile setter when the job involves a shower or steam enclosure (waterproofing failures are expensive and hidden), large-format or natural-stone tile (heavy, unforgiving of an uneven substrate), herringbone, diagonal or other cut-heavy patterns, or a floor that needs leveling. The calculator gives you the quantity and a ballpark cost so you can compare a DIY material bill against an installed quote with confidence.

For related surfaces, see the flooring calculator, paint calculator and drywall calculator.

These figures are estimates only — tile, grout and thinset coverage vary by product, and labor and material prices vary by region and over time. Verify quantities and pricing with a local pro or your tile supplier before you order.