Tile Calculator
Choose the room shape, enter tile size and grout joint, and get base tile count, the order with waste, and full boxes — with a scaled preview of your tiling.
Calculate
Your values convert when you switch units.
Order tiles
The formula
Project area is a rectangle (L×W), circle (π(d/2)²), or L-shape (outer rectangle minus the cut-out). Subtract areas to skip. Effective tile area includes grout: (tile length + joint) × (tile width + joint). Tile count = area ÷ effective tile area, then apply waste and round up to full boxes. With a tile thickness, grout volume ≈ area × (1 − tile face ÷ module) × thickness.
A = project area · Aₙ = net area · l, w = tile length and width · j = grout joint · aₜ = effective tile area · waste = extra for cuts and breakage · box = tiles per box
Worked example
- Room 5 m × 3.6 m → project area = 18 m²
- Tile 60 cm × 30 cm, grout 3 mm → effective tile area ≈ 0.1827 m²; base ≈ 18 ÷ 0.1827 ≈ 98.5
- With 10% waste → order = ceil(98.5 × 1.1) = 109; at 8 per box → boxes = ceil(109 ÷ 8) = 14
Result: Order 109 tiles (14 boxes)
How tile quantity is calculated
The calculator estimates tile quantity from net area and the effective tile footprint (tile plus grout), then adds layout waste and rounds up to full boxes.
Include grout joints for realistic coverage
Ignoring grout joints can overestimate tile count. The effective module includes tile size plus planned joint width.
Waste varies by layout complexity
Straight lay usually needs about 10%, an offset or brick bond about 12%, and diagonal or herringbone about 15%. Many corners, obstacles, or small cut pieces push waste higher.
Order by full boxes
Suppliers usually sell by box. The calculator rounds up to complete boxes based on your tiles-per-box value.
Interesting facts
Tile calibration matters
Even tiles with nominally identical sizes can vary slightly by batch; check caliber before installation.
Larger tiles can reduce grout lines
Fewer joints can improve visual continuity, but flatness tolerances become more critical with large formats.
Diagonal layouts increase offcuts
45° patterns often need higher waste percentages because perimeter cuts are larger and more frequent.
Box labels may show nominal coverage
Manufacturer box coverage can differ from project reality when custom joint widths are used.
Extra stock helps future repairs
Keeping a few spare tiles from the same batch is useful for future replacements and avoids shade mismatch.
Substrate preparation affects consumption
Uneven substrates can change layout choices and cut quantities, increasing real material demand.
Frequently asked questions
It depends on tile dimensions and grout joint width. This calculator computes exact coverage from your inputs.
Yes. Joints occupy area and affect the total tile count needed for full coverage.
Use about 10% for a straight lay, 12% for an offset or brick pattern, and 15% for diagonal or herringbone layouts. Add more for many corners or small cut pieces.
Yes. Enter the wall as a rectangle (length × height as width), subtract openings, and keep the same tile size and waste logic.
Tiles are purchased as whole pieces. The estimate rounds up after applying waste to avoid shortages.
Enter tiles per box and the calculator divides order quantity by that value, then rounds up to full boxes.
Yes. Enter doors, built-ins, or other untiled patches in "Areas to skip" for a tighter estimate, especially on walls.
Use it if sheet dimensions and joint assumptions match your product; otherwise use sheet coverage from the manufacturer.
Enter the tile thickness. Grout volume = project area × (1 − tile face area ÷ module area) × thickness, where the module includes the joint. It is a planning figure — adhesive and waste are not included.
References
- Ceramic tile installation standards overview Waste and layout factors commonly used in tile estimating.
- SI units for area measurement Square-metre basis for floor and wall tile quantities.