Calculator Tools
Tile Calculator
Estimate tiles, boxes, and cost for any room or wall. Adjustable grout joint, waste percent, L-shape areas, and 8 currencies.
Inputs
Measurement system
Area unit only. Tile size and grout joint can be set separately below.
Surface shape
Use Rectangle for a single floor, wall, or backsplash. Use L-shape to sum two rectangles for an L-shaped room.
Surface dimensions
For a wall, use the wall length and the wall height. For a floor, use the room length and width.
Tile size
Tile presets
Grout joint, waste, and boxes
Common values: 1/16 in (0.0625), 1/8 in (0.125), 1/4 in (0.25), 3 mm, 5 mm.
Set the count printed on your tile box to round the order up to whole boxes.
Cost (optional)
Result
Tiles to buy
65
Order 9 boxes to cover 120 sq ft with a 10% waste allowance.
Surface area
120 sq ft / 11.148 sq m
Length times width of the rectangle you entered.
Tile coverage (with grout)
2.0314 sq ft per tile
(tile width + grout) x (tile height + grout). The unit cell each tile takes up on the wall.
Bare tile area (no grout)
2 sq ft per tile
Tile width times tile height. Useful for comparing tile sizes.
Raw tiles required
59.07
Surface area divided by effective tile area.
Tiles after 10% waste
64.98
Raw tile count multiplied by 1 plus the waste percent.
Boxes to buy
9 boxes (8 per box)
Rounded up so you walk out with full boxes.
Spare tiles included
7
Bonus tiles in the last box, on top of the waste allowance. Save them for repairs.
Math runs entirely in your browser. Nothing is uploaded.
How the math works
- Surface area is the length times the width of each rectangle. For an L-shape, the areas of the two rectangles are added together.
- Effective tile area is (tile width + grout) times (tile height + grout). Each tile installed in a real wall or floor takes up its own footprint plus half of every adjoining grout joint, so the unit cell on the grid is the tile plus a full grout joint on two sides.
- Raw tile count is surface area divided by effective tile area. The waste allowance multiplies that count to cover cuts, breakage, and matching pattern, and then the total is rounded up to whole tiles.
- Whole boxes rounds the tile count up again so you walk out of the store with full boxes only. The difference between boxes and exact tiles is shown as your spare tiles for future repairs.
How much waste should I add?
- 5% is the floor for a tiny backsplash with no cuts at the edges. Use this only when every tile lands on a full grid.
- 10% is the standard rule of thumb for floors and walls with a straight layout. This is what most contractors and tile shops recommend by default.
- 15% is recommended for a diagonal layout. Cuts at the perimeter produce a triangular offcut that is usually unusable.
- 20% is for complex patterns (herringbone, hexagons, mosaics) or any project with many obstructions like cabinets, niches, and pipes.
- Order at least one extra full box of any tile you love. If the line is discontinued, you will be grateful for the spares the next time a tile cracks.
How to use
- Pick imperial or metric, then enter the floor or wall length and width. Switch to L-shape to sum two rectangles.
- Choose a tile preset or type your own tile width and height in inches, centimeters, or millimeters.
- Set the grout joint width in inches or millimeters. Common values are 1/16 in, 1/8 in, 1/4 in, 3 mm, and 5 mm.
- Pick a waste preset (5%, 10%, 15%, 20%) or enter a custom percent for your layout and pattern.
- Optionally enter tiles per box to round to whole boxes and a price per box or per tile to get a total cost.
- Click Copy summary to send the estimate to your notes, contractor, or shopping list.
About this tool
Tile Calculator estimates how many tiles, boxes, and total dollars you need for any tile job by combining the surface area, the tile size, the grout joint width, and a waste allowance. Enter a rectangular floor, wall, or backsplash, or switch to L-shape to sum two rectangles for an L-shaped room. Tile dimensions accept inches, centimeters, or millimeters, with one-click presets for common nominal sizes including 12 x 12, 12 x 24, 6 x 6, subway, and large-format porcelain. Grout joints accept inches or millimeters and the math uses the standard rule that each tile is responsible for half the joint on every side, so the effective tile area is (width + grout) x (height + grout). The waste field defaults to the contractor standard 10 percent with presets for 5 percent backsplashes, 15 percent diagonal layouts, and 20 percent for herringbone, hex, and complex mosaics. Optional tiles-per-box rounds the order up to whole boxes and reports the spare tiles you walk out with, and an optional price per tile or price per box in eight currencies produces a total project cost. All math runs locally; nothing is uploaded.
Free to use. Works in your browser. No signup, no login.
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