Tile Calculator — Number of Tiles & Boxes

Calculate tiles needed for floors and walls including waste factor and box count.

About this calculator

A tile calculator works out how many tiles you need to cover a floor or wall, including the wastage allowance for cuts and breakages. Tile is sold by the box (usually 8–15 tiles per box depending on size), and buying just enough usually leaves you short — you almost always need a wastage margin of 10–15%.

Tile size affects both the visual outcome and the practical wastage. Small mosaic tiles (50 mm) waste 5–8%; standard 300 × 300 floor tiles waste 7–10%; large format 600 × 600+ tiles waste 12–15% because each cut is bigger. Diagonal laying patterns add another 5% on top.

Formula

N = \left\lceil \frac{A \times (1 + w)}{a} \right\rceil

  • N — Number of tiles required (rounded up)
  • A — Floor/wall area in m²
  • a — Area of one tile in m²
  • w — Wastage factor (0.10 = 10%, etc.)

Worked example

Inputs: Floor: 4 m × 5 m · Tile: 600 mm × 600 mm · 12% wastage

  1. Floor area = 4 × 5 = 20 m²
  2. Area per tile = 0.6 × 0.6 = 0.36 m²
  3. Tiles needed without wastage = 20 ÷ 0.36 = 55.6 → 56
  4. With 12% wastage = 56 × 1.12 = 62.7 → buy 63 tiles
  5. If box has 4 tiles → buy 16 boxes (64 tiles)

Frequently asked questions

Should I keep extra tiles after the job?

Yes — always keep 5–10 spare tiles from the same batch. Tile dye batches vary, and you may not be able to match the exact colour 2–3 years later when a tile cracks and needs replacing. Store spares flat in their original packaging in a dry place.

How much adhesive and grout do I need?

For floor tiles: 4–5 kg of cement-based adhesive per m². For wall tiles: 3–4 kg/m². Grout usage depends on joint width but typically 0.3–0.5 kg/m² for 3 mm joints, 0.8–1.0 kg/m² for 8 mm joints. Read your adhesive/grout bag for exact coverage.

Related calculators

Flooring Calculator Paint Calculator Room Area

More calculators

EMI Calculator Mortgage Calculator SIP Calculator Compound Interest GST / VAT Calculator Salary Calculator Unit Converter Currency Converter Scientific Calculator Concrete Calculator Paint Calculator Calorie / TDEE Body Fat Macro Calculator O-Ring Sizes Bolt & Nut Sizes Pipe Sizes Wire Gauge AWG Needle Gauge Chart IV Cannula Sizes Suture Sizes Catheter French Sizes Drug Dosage See all 90+ calculators ›