Free · no sign-up · runs in your browser
Floor Tile Calculator
Room size + tile size + grout width in, boxes out. Tiles, waste and coverage cost with the grout joint counted — the number you hand the clerk at the tile aisle.
Tile & box calculator
Every figure updates as you type — no submit button.
L-shaped room, closet or alcove? Add each rectangular section separately and sum the boxes — one rectangle will under-count.
Boxes to buy
130
130 tiles · 10% waste · 1 tile per box
Scaled layout preview
How it works
Length and width in feet. Use the largest rectangle; odd shapes get added separately.
Pick a preset or type a custom size in inches, then set the grout joint — 1/8 in is the usual floor joint.
Waste is added, tiles per box divides, and the count rounds up. Twelve by ten feet at 12×12 in with a 1/8 in joint needs 118 tiles, 130 with 10% waste.
What the numbers mean
A tile plus its joint is the real module: 12 in tile + 1/8 in joint covers 12.125 in. Wider joints mean slightly fewer tiles.
10% covers straight-lay cuts. Use 15% for diagonal or herringbone. Tiles under 6 in are floored at 10% whether you ask for it or not.
You cannot buy a partial box, so the count rounds up to the next full box and the spare tiles are shown rather than hidden.
The room is measured in feet and tiles in inches, so the area is shown in sq ft and sq m — the quickest way to catch a metres-into-feet typo.
The preview shades the strips that get cut at the wall and reports the cut width, so you know the offcut is usable or not.
Add each rectangular section separately and sum the boxes. A single rectangle always under-counts an L-shape, closet or alcove.
FAQ
How many tiles for a 12×10 ft room?
120 sq ft of floor takes about 118 tiles of 12×12 in once the 1/8 in grout joint is included. Add 10% for cuts and breakage and you need 130 tiles — 11 boxes if the box holds 12, or 130 boxes if it holds 1.
How much waste should I add?
10% for a straight lay in a plain rectangle. Go to 15% for diagonal, herringbone or a room with many doorways and pipes. 0% is never realistic — one broken tile means a second trip.
Does grout width change the tile count?
Slightly, yes. Joints add coverage, so a 1/8 in joint means a 12×12 in tile actually covers 12.125 in and you need a couple fewer tiles. Wide 1/2 in joints save a few more.
What about L-shaped rooms and closets?
Measure each rectangle on its own, run the calculator for each, then add the boxes together. Never bend a single rectangle around a corner — that under-counts the floor.
Feet or inches — what do I enter?
Room dimensions in feet, tile size in inches, grout in inches. The area is printed in both sq ft and sq m so a metric slip-up is obvious before you buy.
Can I use this for wall tile or a shower?
Yes — same math. Enter the wall area as length × width in feet (height becomes the second dimension) and add 15% waste, which is normal for wall work.
Is my data stored anywhere?
No. The whole calculation runs in your browser — nothing is uploaded, no account, and it keeps working while you stand in the store with a bad signal.
Why round up to whole boxes?
Stores sell full boxes. The result gives the boxes to buy plus how many spare tiles you end up holding, so you can decide whether to drop a box.
120.0 sq ft · 130 tiles
130 boxes