Tile Calculator

Enter floor or wall area and tile size to instantly calculate the number of tiles needed. Accounts for grout spacing and waste with this free online tile calculator.

How to Use

  1. Enter area dimensions

    Input the width and length of the floor or wall to be tiled.

  2. Select tile size

    Choose or enter the tile dimensions and grout spacing.

  3. View results

    Click Calculate to see the number of tiles needed and total coverage area.

What is tile quantity estimation?

Tile quantity estimation is the process of calculating in advance how many tiles a job needs by dividing the area of the floor or wall to be covered by the area of a single tile. Even for the same area, the number of tiles required changes dramatically with the tile format (for example, 300×300mm vs. 600×600mm), so it forms the basis for quoting and ordering materials.

Why it matters

  • Cost estimating: Tiles are usually sold by the box, so an accurate count is your budget.
  • Allowing for waste: Cuts around corners and columns, plus breakage during installation, make a surplus essential.
  • Color consistency: Even the same product varies in shade from one production lot to another, so buying enough at once keeps colors from clashing if a repair is needed later.

The formula

Tile quantity is found by adding a waste allowance to the area ratio and rounding up.

Tile area (m²) = (tile width cm ÷ 100) × (tile length cm ÷ 100)
Without waste = ⌈room area ÷ tile area⌉
Tiles needed = ⌈(without waste) × (1 + waste% ÷ 100)⌉

Example: For a 4m × 5m room (20m²) with 600×600mm tiles (0.36m²) and a 10% waste allowance
Without waste = ⌈20 ÷ 0.36⌉ = ⌈55.6⌉ = 56 tiles
Tiles needed = ⌈56 × 1.10⌉ = ⌈61.6⌉ = 62 tiles (6 spare).
⌈ ⌉ means round up, and since tiles cannot be bought in half units, the result is always rounded up.

Frequently Asked Questions

How do I calculate the number of tiles?
Divide the installation area by the area of a single tile and round up, then multiply by the waste allowance percentage and round up again. Because tiles cannot be bought in half units, the result is always rounded up to a whole number.
Why is a waste allowance needed?
Breakage occurs while cutting during installation, and pieces must be trimmed around corners and columns. A 10–15% allowance is generally recommended, and diagonal layouts may require as much as 15–20%.
How do I choose the tile size?
For small spaces such as bathrooms, 20×20cm to 30×30cm works well, while 60×60cm to 80×80cm suits large living rooms. Large tiles have fewer grout lines and look clean but can produce more cutting waste, whereas small tiles are easier to lay around curves and drains.
How do I measure the floor area?
Use a tape measure to record the room's width and length in meters. For non-rectangular spaces, split the area into several rectangles, calculate each, and add them up; if there are columns or projections, subtract their area.
What grout spacing is typical?
Standard grout spacing is 2–3mm, while large tiles (600×600mm and above) suit 3–5mm. Including the grout in the tile size when calculating gives a more accurate count.
Do diagonal (diamond) layouts need more tiles?
Yes. A diagonal layout requires more triangular cuts where it meets the walls, so it needs roughly 10–15% more tiles than a standard grid layout. It's best to raise the waste allowance to 15–20%.
How many boxes of tiles should I buy?
Divide the calculated number of tiles needed by the number per box and round up. For example, if you need 62 tiles and a box holds 4, you buy 16 boxes (64 tiles). Buying by the box naturally provides extra surplus.
What should I do with leftover tiles?
It's wise to keep some spares in case you need to replace a tile that cracks or is damaged after installation. Since the same product can differ in shade between production lots, it can be hard to find a matching color later.
Updated 2026 pricing

Related Calculators

Chinese Zodiac Calculator(year - 4) % 12Barcode Check Digit10 - (Σ(digit × weight) % 10)Paint CalculatorpaintL = wallArea × coats / coverageRateBrick Calculatorbricks = wallArea / (brickW+mortar) × (brickH+mortar)