Tile Calculator
Calculate how many tiles, adhesive and grout you need for floors or walls.
Please note: Material estimates for planning only. Always confirm quantities against your drawings, local building codes and supplier specifications before ordering. Structural work requires a qualified engineer.
What the Tile Calculator does
Tile count divides the surface area by the area each tile occupies, including its grout joint. Ignoring the joint overestimates how many tiles fit, which is why small mosaics with wide joints need noticeably fewer tiles than a naive count suggests.
Formula
Effective tile area = (Tile length + Joint) × (Tile width + Joint)Tiles = ⌈Surface area ÷ Effective tile area × (1 + Waste %)⌉Boxes = ⌈Tiles ÷ Tiles per box⌉
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Area length | number | Yes | Accepts more than 0. |
| Area length unit | one of 6 options | Yes | — |
| Area width or height | number | Yes | Accepts more than 0. |
| Area width or height unit | one of 6 options | Yes | — |
| Tile length | number | Yes | Accepts more than 0. |
| Tile length unit | one of 5 options | Yes | — |
| Tile width | number | Yes | Accepts more than 0. |
| Tile width unit | one of 5 options | Yes | — |
| Grout joint width | mm | Yes | Accepts 0 or more. |
| Tile thickness | mm | Yes | Accepts 1 or more. |
| Waste allowance | % | Yes | Extra material for cuts, breakage and offcuts. 5–10% is typical, more for complex layouts. |
| Tiles per box | number | Optional | Accepts 1 or more. |
| Price per tile | selected currency | Optional | Accepts 0 or more. |
| Currency | one of 10 options | Optional | — |
How to use it
- Choose Area length unit and Area width or height unit.
- Enter Area length, Area width or height, Tile length and Tile width and 3 more.
- Optionally add Tiles per box and Price per tile.
- Select Calculate.
Worked example
A 3 m × 2.4 m wall with 600 × 300 mm tiles, 3 mm joints, 10% waste, 6 per box.
- Length
- 3 m
- Width
- 2.4 m
- Tile
- 600 × 300 mm
- Grout
- 3 mm
- Waste
- 10
Area 7.2 m². Effective tile 0.603 × 0.303 = 0.1827 m² → 39.4 tiles, +10% = 44 tiles = 8 boxes.
Frequently asked questions
Why include the grout joint?
Because each tile occupies its own footprint plus one joint width. With 300 mm tiles and 5 mm joints, ignoring it overstates tile count by around 3%.
How much extra should I buy?
10% for a straight layout, 15% for diagonal, plus a spare box for future repairs.