How it works
Give the calculator two things — how much floor you are covering and how big each tile is — and it does the rest.
Enter the area
Type your room length and width, or switch to total area if you already know the square footage.
Set your tile size
Enter the width and height of a single tile in inches. Add tiles-per-box if you want a box count.
Get tiles & boxes
See exactly how many tiles to buy — waste included — and how many boxes that works out to.
Buying the right amount of tile
The core calculation is simple: work out the area you are covering, work out the area of a single tile, and divide one by the other. The catch is that tiles come in inches while rooms are measured in feet, so the area of a 12 × 12 inch tile is one square foot, while a 6 × 24 inch plank tile is exactly one square foot too — but a 4 × 4 inch tile takes nine to cover the same space.
The number that saves projects is the waste allowance. Every cut at a wall or around a fixture leaves an offcut you usually can't reuse, and a few tiles always break. Ten percent extra covers a normal straight lay; step up to fifteen for diagonal and herringbone patterns, which generate far more cuts.
One more reason to buy extra now: tile is produced in batches, and colors can shift slightly between them. Buying your whole job — plus spares — from a single batch means a future repair still matches. Keep a few loose tiles in the garage when you're done.
Frequently asked questions
How many 12×12 tiles do I need for 120 square feet?
A 12 × 12 inch tile covers one square foot, so you need 120 tiles plus waste — about 132 tiles with a 10% allowance, or roughly 14 boxes if a box holds 10.
How much extra should I buy for cuts and breakage?
Add 10% for a standard straight layout and 15% for diagonal or herringbone patterns, or rooms with lots of corners and fixtures.
Does this work for wall tile too?
Yes. Switch to "Total area", enter the wall square footage, and it works the same way as a floor.
Why round up to whole boxes?
Stores sell tile by the box, not the individual piece. Entering tiles-per-box rounds your total up so you order what you can actually buy.
More material calculators
Estimates are for planning only. Confirm tile counts and batch availability with your supplier before ordering.