Tile Calculator

Find out how many tiles you need for a floor or wall, based on your area and tile size — with waste and estimated cost included.

How to measure an area — length times width Length Width
Measure the area — length × width.

How to calculate how many tiles you need

The number of tiles depends on the area you are covering and the size of each tile:

Tiles needed = area ÷ area of one tile × (1 + waste %)

This calculator converts your tile dimensions from inches to square feet (width × height ÷ 144), divides your total area by that figure, adds a waste allowance, and rounds up. The same method works for both floors and walls.

How much extra tile should you buy?

LayoutRecommended waste
Straight, grid layout10%
Diagonal layout15%
Complex rooms or many cuts15–20%
Small mosaic or patterned tile15%+

Good to know

  • Keep spares. Tile dye lots vary between batches, so buy enough at once and keep a few spares for repairs.
  • Don't forget mortar and grout. Coverage depends on tile size and spacing — check the product bag.
  • Measure walls separately. For a backsplash or shower, calculate each wall as its own area and add them up.

Frequently asked questions

How many 12x12 tiles do I need for 100 sq ft?
A 12 × 12 in tile covers exactly 1 sq ft, so 100 sq ft needs 100 tiles — plus about 10% waste, which comes to 110 tiles.
How much extra tile should I buy?
Around 10% for a straight grid layout, and 15% or more for diagonal patterns, mosaics, or rooms with lots of cuts.
How do I calculate tiles for a wall?
Exactly like a floor: measure the wall height and width for the area, divide by one tile's coverage, and add waste.
Should I buy by tile or by box?
Stores sell tile by the box. Take the number of tiles here and divide by the tiles-per-box on the carton, then round up.

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