NOVORY

Tile Calculator

Calculate how many tiles you need for any room, with waste allowance for cuts and breakage.

Quick answer

110 tiles (11 boxes of 10). On a diagonal, budget 115.

Calculator

ft
ft
in
in

How it works

Room length × Room width = Room area

The calculator multiplies the room's length by its width to get the total floor area that needs to be tiled.

Tile length × Tile width = Tile area

The same calculation is done for a single tile. Tile dimensions are entered in inches (imperial) or centimeters (metric) and converted to the same unit as the room dimensions.

Room area ÷ Tile area = Tiles required

Dividing the room area by the tile area gives the base number of tiles. The result is rounded up to the nearest whole tile, then increased by the waste percentage.

Worked example

A 12 ft × 10 ft room with 12 in × 12 in tiles:

12 × 10 = 120 sq ft

12 × 12 in = 1 sq ft per tile

120 ÷ 1 = 120 tiles

120 × 1.10 = 132 tiles (with 10% waste)

Purchase 132 tiles for this project.

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Counting tiles is easy — it's the waste percentage that ruins budgets. A straight grid in a square room wastes 10%; the same tile on a diagonal in a hallway full of doorways can waste 20%. And unlike paint, you can't buy 'a little more' later: dye lots shift, and three replacement tiles will never match.

This calculator divides your room area by the tile area (using the nominal size you enter), rounds up to whole tiles, then adds your waste allowance. Measure the tile, not the box label — a nominal '12-inch' tile is often 11¾ inches, and that quarter inch compounds across a room.

How to measure for tile

  1. Measure the room's length and width in feet, wall to wall. Include closets and alcoves that will be tiled — measure them as separate rectangles.
  2. Measure one actual tile in inches (length × width). Don't trust the nominal size on the box.
  3. Pick waste by layout: 10% for a straight grid, 15% for diagonal or rooms with lots of cuts, 20% for herringbone.
  4. Round up to whole tiles, then check how tiles are sold — most are boxed (e.g., 10 per box), so round up to full boxes.

Waste allowance by layout

LayoutWasteWhen to use it
Straight grid10%Square rooms, few obstacles
Diagonal15%Angled layouts, hallways with doorways
Herringbone / chevron20%High-cut patterns
Large format (24 in+)15%Fewer tiles, but every cut wastes more

Percentages assume a competent installer. First-timers: take the next bracket up.

Worked example: 12-inch tiles for a 10×10 floor

A 10 ft × 10 ft floor with 12 × 12 in tiles, straight grid:

  1. Room area: 10 × 10 = 100 sq ft.
  2. Tile area: (12 ÷ 12) × (12 ÷ 12) = 1 sq ft per tile.
  3. Tiles: 100 ÷ 1 = 100, rounded up.
  4. With 10% waste: 100 × 1.10 = 110 tiles.

110 tiles (11 boxes of 10). On a diagonal, budget 115.

Pro tips for buying tile

  • Buy every tile from the same dye lot — check the lot code on every box before you leave the store.
  • Dry-lay the first row: a sliver cut against the most visible wall is the mark of an amateur; shift the layout to split the difference.
  • Large-format tiles need a flat floor (⅛ in over 10 ft). Grind high spots now or live with lippage.
  • Keep a half-box of spares. Future you, replacing one cracked tile, will be grateful.

How to use the tile calculator

1. Choose your unit system — Imperial (feet and inches) or Metric (meters and centimeters).

2. Enter the length and width of the room you are tiling.

3. Enter the length and width of a single tile — in inches for imperial or centimeters for metric.

4. Select a waste factor — 10% is recommended for standard layouts.

5. Click Calculate to see how many tiles you need, with and without waste.

How tile quantity is calculated

The calculator first determines the room area by multiplying the room length by the room width. It then calculates the area of a single tile the same way. Dividing the room area by the tile area gives the base number of tiles required.

The result is rounded up to the nearest whole tile, since you cannot buy partial tiles. The waste factor is then applied to account for cuts, breakage, and future repairs.

Why add a waste factor for tiles?

Tile installations always produce waste. Tiles must be cut to fit along edges and around obstacles, and some tiles will break during cutting or installation. A waste factor ensures you have enough tiles to complete the job without having to place a second order.

It also leaves you with spares for future repairs. Matching tiles years later can be difficult if the design has been discontinued.

Tile calculator example

Suppose your room is 12 feet by 10 feet, and you are using 12-inch by 12-inch tiles.

Room area: 12 × 10 = 120 square feet.

Tile area: 12 × 12 = 144 square inches = 1 square foot.

Tiles required: 120 ÷ 1 = 120 tiles.

With 10% waste: 120 × 1.10 = 132 tiles.

You should purchase 132 tiles for this project.

Frequently Asked Questions

How do I calculate how many tiles I need?+
Measure the room area (length × width) and the area of a single tile (tile length × tile width). Divide the room area by the tile area to get the number of tiles. Add a waste factor — typically 10% — to account for cuts, breakage, and future repairs.
How much waste should I add for tiles?+
A 10% waste factor is standard for most tile installations. For complex layouts like diagonals or herringbone, use 15%. For simple straight layouts in rectangular rooms with few obstacles, 5% may be sufficient. Always keep a few extra tiles for future repairs.
How do I calculate tile area?+
Multiply the tile length by the tile width. For example, a 12-inch by 12-inch tile has an area of 1 square foot. A 60 cm by 60 cm tile has an area of 0.36 square meters. Make sure your tile dimensions use the same unit system as your room dimensions.
How many extra tiles should I buy?+
Always buy 10–15% more tiles than the calculated amount. This covers cuts around edges and obstacles, breakage during installation, and tiles you may need years later if one cracks and needs replacing. Discontinued tiles can be impossible to match later.
Do I need to account for grout lines?+
Grout lines slightly reduce the number of tiles needed, but the effect is small for most projects. For simplicity, the calculator does not factor in grout width. If you are installing tiles with very wide grout lines (over 1/4 inch), you may need slightly fewer tiles than calculated.

Related Guides

How Many Tiles Do I Need for a 10x10 Floor?How Many Tiles Do I Need for a 12x12 Floor?

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