Tile Calculator
Calculate exactly how many tiles you need for flooring, walls, or backsplashes.
Reviewed by the ToolNestr Editorial Team — July 2026
How the tile calculator works
The tile calculator determines how many tiles you need for a floor or wall based on the area dimensions and the tile size. It calculates the total area in square feet, computes how many tiles cover that area, and adds a waste factor for cuts, breakage, and future repairs.
To use the calculator, enter the length and width of the area in feet, then the tile dimensions in inches (most tile is sold by inch measurements). Select your waste factor — 10% for straightforward installations, 15% for diagonal or patterned layouts. If you are buying tiles by the box, enter the box coverage to see how many boxes to purchase.
Tile installation is one of the most precise finishing trades in construction. Unlike paint or flooring, tile cannot be trimmed to fractional sizes easily — each cut requires a wet saw or tile cutter. Having extra tiles is essential not just for installation but for future repairs, as tile dye lots vary and matching old tile years later is nearly impossible.
Measure the area
Measure the length and width of the floor or wall space to be tiled.
Enter tile size
Input the tile length and width in inches. Common sizes include 12x12, 6x24, and 18x18.
Buy the right amount
Order the calculated number of tiles plus waste. Keep the extra boxes unopened for returns.
The formula explained
Area calculation
Area = L × W. A 10′ × 8′ room = 80 sq ft.
Tile area in square feet
Tile sq ft = (TL × TW) / 144. A 12″ × 12″ tile = 144 / 144 = 1 sq ft. A 6″ × 24″ tile = 144 / 144 = 1 sq ft.
Tile count
Tiles = Area ÷ tile sq ft. For 80 sq ft with 12″ tiles: 80 ÷ 1 = 80 tiles. With 10% waste: 80 × 1.1 = 88 tiles.
Worked example
A 12′ × 10′ bathroom floor using 6″ × 24″ tiles with 15% waste for a herringbone pattern.
Use cases for the tile calculator
Bathroom renovation
Tile the floor, shower walls, and backsplash. Each surface is calculated separately. Subway tile on walls, hexagon on the floor — the calculator works with any tile shape and size.
Kitchen backsplash
A kitchen backsplash typically covers 30-40 sq ft. Use mosaic tiles on mesh sheets for easy installation. The calculator handles small tiles that come in sheets as well as individual tiles.
Entryway flooring
Porcelain or ceramic tile in the entryway creates a durable, waterproof surface. Large-format tiles (24x24 or 36x36) give a modern look and require fewer grout lines.
Commercial spaces
Restaurants, retail stores, and offices use heavy-duty commercial tile. Calculate large areas and order in bulk. Always add a full extra box for future maintenance and repairs.
Tips for tiling success
Dry lay first
Lay out a row of tiles without adhesive to check the layout and spacing. This reveals if you will have thin slivers of cut tile at the edges. Adjust the starting point to center the pattern and avoid cuts smaller than half a tile width.
Use spacers consistently
Tile spacers ensure even grout lines. Choose the spacer size based on the tile: 1/16 inch for rectified tiles (precision-cut with tight joints), 1/8 inch for standard tiles, and 1/4 inch for natural stone or outdoor tiles where thermal expansion is a concern.
Keep spare tiles for repairs
Save at least 5-10 spare tiles from your installation. If a tile cracks or a plumbing leak damages the floor years later, you will have matching tiles available. Tile dye lots change over time and discontinued patterns are common.
Related calculators
Frequently asked questions
How much extra tile should I buy?
Always buy 10-15% extra for waste. Simple square layouts need 10%. Diagonal layouts, herringbone patterns, and rooms with many corners need 15%. Keep extra tiles for future repairs.
What does "nominal" tile size mean?
Nominal size is the advertised size, but actual tile dimensions may vary by 1-2 mm. For example, a 12x12 inch tile may actually measure 11.75 x 11.75 inches. Always measure your actual tiles before calculating.
How do I tile around obstacles?
Measure the full area including the obstacle, calculate tiles for the full area, then subtract waste. It is usually easier to tile the whole area and cut around obstacles than to calculate exact cut pieces.
Do I need to account for grout lines?
For large tiles (12 inches and up), grout lines of 1/8 inch add minimal difference. For small mosaic tiles, grout lines can reduce the tile count by 5-10%. This calculator does not deduct for grout.
Sources & references
This tool uses standard formulas and reference values from:
- • American Concrete Institute — ACI 318, Building Code Requirements for Structural Concrete. concrete.org
- • ICC — International Residential Code (IRC), span, footing and framing tables. codes.iccsafe.org
- • APA – The Engineered Wood Association, allowable span and load guidance.
Estimates for planning only. Span, load and code values vary by jurisdiction — verify against your local adopted code and a licensed engineer before building.