Area Measurements
Tile Details
Material Coverage
Enter your dimensions
Input your room dimensions and tile size to calculate exactly how many tiles and boxes you need to order.
What is a tile calculator?
A tile calculator is a vital tool for planning flooring, bathroom, and kitchen renovations. It takes the total area you wish to tile and divides it by the size of the individual tiles you have selected, giving you an accurate count of how many tiles you need to purchase.
Crucially, this tool automatically accounts for necessary waste (for cuts, breakages, and spares) and translates the total tile count into boxes, adhesive bags, and grout, ensuring you arrive at the hardware store completely prepared.
How to use this calculator
- 1
Measure Your Area: Enter the length and width of the surface to be tiled in metres. Exclude doors, large windows, or built-in cabinets using the 'Openings' field.
- 2
Input Tile Specs: Provide the exact dimensions of your chosen tile in millimetres and how many tiles come in a standard box.
- 3
Select Layout: Choose straight, diagonal, or patterned layout to automatically adjust the recommended waste percentage.
- 4
Adjust Coverage: If your chosen brand of adhesive or grout differs from the defaults, update their coverage rates for precise estimates.
Important Tiling Factors
How Tile Quantity is Calculated
First, we find the total surface area by multiplying length by width and subtracting openings. Then we calculate the area of a single tile. Dividing the room area by the single tile area gives the absolute minimum 'base' tiles required before adding waste.
Why Waste Allowance Matters
Rooms are rarely perfectly square, and walls are never perfectly straight. Tiles must be cut to fit edges, corners, and fixtures. You will also need a few spares for future repairs. Standard straight layouts require 10% waste, but complex layouts need more.
How Many Tiles in a Box?
Hardware stores sell tiles by the box, not individually. Box quantities vary wildly by tile size. A box of small subway tiles might contain 50 tiles, while a box of large 600x600mm porcelain tiles might only contain 4. Always check the packaging label.
Estimating Adhesive & Grout
Adhesive: As a general rule of thumb, a standard 20kg bag of tile adhesive covers approximately 4-5 square metres when using a 10mm notched trowel. Larger tiles require a larger trowel notch, meaning you will use more adhesive per square metre.
Grout: Grout usage depends entirely on the width of your grout joints and the thickness of the tile. A standard 5kg bag of grout typically covers 8-10 square metres for average-sized tiles with a 2-3mm joint. Very small tiles (like mosaics) have many more joints and require much more grout.
Common calculation mistakes
Forgetting to subtract large openings (like doors and large windows) from wall area calculations.
Not ordering enough waste for diagonal layouts (which require at least 15% extra).
Mixing up mm and cm when entering tile sizes, resulting in wildly incorrect tile counts.
Buying exact box counts without checking if the tile batch/lot numbers match.
Failing to keep spare tiles. If a tile breaks 3 years later, finding an exact color match is nearly impossible.
Example Calculations
Floor Tile Calculation
Tiling a 4m × 5m living room with 600mm × 600mm floor tiles, straight layout.
- • Area = 4 × 5 = 20m²
- • Tile Area = 0.6 × 0.6 = 0.36m²
- • Base Tiles = 20 / 0.36 = 55.5 tiles
- • Plus 10% Waste = 61.1 (Round up to 62 tiles)
- • If 4 tiles per box, you need 16 boxes.
Wall Tile Calculation
Tiling a 3m × 2.4m bathroom wall, minus a 1.6m² window. Using 300mm × 100mm subway tiles.
- • Gross Area = 3 × 2.4 = 7.2m²
- • Net Area = 7.2 - 1.6 = 5.6m²
- • Tile Area = 0.3 × 0.1 = 0.03m²
- • Base Tiles = 5.6 / 0.03 = 186.6 tiles
- • Plus 10% Waste = 205.3 (Round up to 206 tiles)
Frequently Asked Questions
Important Disclaimer
Related Calculators
Calculation method, worked example and reference
What this calculator does and formula: Tile count = net surface area ÷ tile face area, rounded up, then increased for the selected waste and layout.
Variables and units: Enter values in the units named by the controls. The calculator converts through its internal base unit or applies the displayed geometric or financial relationship before rounding the presented result.
Verified worked example: A 10 m² surface using 0.25 m × 0.40 m tiles has 0.10 m² per tile and needs 100 tiles before waste.
Result interpretation, assumptions and practical limits: Actual needs depend on grout joints, cuts, pattern, shade batches and breakage. Substrate, waterproofing and movement joints require specification review.
Professional check: Treat the result as a planning estimate. Where safety, regulated work, contracts or significant money are involved, verify inputs and the result with the governing standard, manufacturer data and an appropriately qualified professional.