Enter a room's dimensions and tile size to calculate how many tiles you need, with waste allowance and total cost.
How to Use the Tile Calculator
Enter the room's length and width in feet, then pick a tile size from the presets or switch to Custom to type in your own width and height. Waste percentage and price per tile are both editable — leave price at zero if you're just working out quantities.
Room area divided by a single tile's area gives the raw count, then waste percentage and rounding do the real-world adjusting.
tile area (sq ft) = (tile width in × tile height in) ÷ 144
tiles needed = room area ÷ tile area × (1 + waste %)A plain rectangular room laid square needs a modest waste allowance, because cuts only happen at the perimeter. Add a diagonal layout, an intricate pattern, or a room with jogs and alcoves, and the waste climbs fast — every cut around a doorway, a corner, or an angled edge produces a piece too small to reuse. The default 10% here is a reasonable floor for a simple room, not a ceiling for every layout. Switching from a straight-lay 12×12 tile to a diagonal layout on the same room is one of the more common reasons a real order ends up 15–20% over the flat math.
Why the Count Always Rounds Up
The final tile count is always rounded up, even when the raw math lands at, say, 131.2 tiles. A fraction of a tile isn't something a supplier sells, and running short mid-job to save the cost of a partial box is a worse outcome than buying a few extra — a mismatched dye lot on a reorder, a delayed delivery, a second trip to the store mid-install. Buying slightly over the bare minimum is the cheaper mistake of the two, and it's why this calculator never shows a decimal in the final tile count.