Tile Calculator
Choose a mode, enter your dimensions, and get a full tile estimate with grout, adhesive, and cost breakdown
10% waste is recommended for most floor jobs.Project Summary
Calculation Breakdown
Grout & Adhesive Estimate
Shopping List
Full Project Details
How Many Tiles Do I Need? The Complete Guide
Understand tiles per m², tile coverage, joint sizing, and waste factors — for perfect results every time
Calculating tile quantities starts with one simple formula: divide the total area by the area of a single tile. In practice, you measure the room in metres, square it, and divide by the tile face area — then add a waste percentage to account for cuts and breakage.
The exact formula for tiles per m² is: 1,000,000 ÷ (tile length in mm × tile width in mm). For a 300×300mm tile: 1,000,000 ÷ (300 × 300) = 11.1 tiles/m². For a 600×600mm tile: 1,000,000 ÷ (600 × 600) = 2.78 tiles/m². Grout joints slightly reduce the effective area per tile but are rarely large enough to matter for quantity calculations — the waste allowance covers this.
Always measure the room at its widest points, including any alcoves or recesses. Measure twice — buying too few tiles mid-project is a common and costly mistake, especially if the batch is discontinued or the colour varies between batches. Always buy all tiles from the same batch code (shown on the box lid).
Tile Size Chart — Coverage & Tiles Per m² Reference
Popular tile sizes worldwide with tiles/m², tiles/ft², and practical use cases for each format
| Tile Size | Dimensions (mm) | Tiles / m² | Tiles / ft² | Best Used For |
|---|---|---|---|---|
| Small Mosaic | 50 × 50 | 400 | 37.2 | Feature strips, borders, shower floors |
| Subway / Metro | 75 × 150 or 100×200 | 89 / 50 | 8.3/4.6 | Kitchen splashbacks, bathroom walls |
| Small Square | 150 × 150 | 44.4 | 4.1 | Classic bathroom walls, vintage style |
| Standard 300×300 | 300 × 300 | 11.1 | 1.03 | Bathrooms, kitchens, general floors |
| Rectangular 300×600 | 300 × 600 | 5.6 | 0.52 | Bathroom walls, modern interiors |
| 400 × 400 | 400 × 400 | 6.25 | 0.58 | Large bathrooms, hallways |
| Popular 600×600 | 600 × 600 | 2.78 | 0.26 | Open-plan floors, living rooms, commercial |
| Large Format 600×1200 | 600 × 1200 | 1.39 | 0.13 | Luxury interiors, feature walls, hotel lobbies |
| Plank / Wood-Look | 150 × 900 | 7.41 | 0.69 | Wood-effect flooring, hallways |
| Hexagon 150mm | 150 (point-to-point) | ~52 | ~4.8 | Bathroom floors, feature walls, vintage |
How to Use This Tile Calculator — Step-by-Step
Complete guide to all five calculator modes with expert tips for each room type
- 1
Choose the Right Calculator Mode
Floor Area — calculates tiles for a floor surface. Enter room length × width, tile size, and waste %. Use "Add Obstacle" to deduct islands, bath trays, or fitted units. Wall Area — for a single wall surface. Add openings for windows/doors. Full Room — calculates floor + all four walls as one combined project (great for bathrooms). Grout Only — estimates grout and adhesive for a known tiled area. Cost Estimate — total material and labour cost breakdown.
- 2
Measure Carefully — Tips for Accuracy
Measure the room at its longest and widest points. For irregular rooms, break into rectangles and add them up. For walls, measure height (floor to ceiling or to the tiling height) and the full length. Measure from skirting to skirting for floors. Always double-check measurements before ordering.
- 3
Select Tile Size — or Enter Custom Dimensions
Choose from the preset sizes or select "Custom size…" to enter any tile dimensions in millimetres. The calculator works out tiles per m² from your exact tile size. For rectified tiles (precision-cut), you can use narrower grout joints (1–2 mm); for calibrated tiles, use 3–5 mm joints.
- 4
Choose the Right Waste Percentage
Select 10% for straightforward rectangular rooms with straight-lay tiles. Choose 15% for rooms with many pipes, projections, or a bathtub surround. Select 20% for diagonal tile patterns, herringbone, chevron, or any curved surfaces. Add extra for very large tiles (600mm+) due to handling risk.
- 5
Review the Full Breakdown and Shopping List
The results panel shows total tiles, tiles/m², grout bags, adhesive quantity, and a complete shopping list. Use the Grout Only mode if you want a more detailed estimate of grout and adhesive based on exact joint width and tile thickness. Copy or share the estimate with your builder or supplier.
Grout & Adhesive Guide — Complete Reference
How much grout and adhesive you need, which products to use, and application tips from professionals
| Tile Size | Joint Width | Grout (kg/m²) | Floor Adhesive (kg/m²) | Wall Adhesive (kg/m²) |
|---|---|---|---|---|
| 100–200 mm | 2 mm | 0.5–0.8 | 6–8 | 4–5 |
| 200–300 mm | 2–3 mm | 0.6–1.0 | 6–8 | 4–6 |
| 300×300 mm | 3 mm | 0.8–1.2 | 6–8 | 4–6 |
| 300×600 mm | 3 mm | 0.6–1.0 | 7–9 | 5–6 |
| 600×600 mm | 3–5 mm | 0.5–0.8 | 8–10 | 6–8 |
| 600×1200 mm | 3–5 mm | 0.4–0.6 | 9–12 | 7–9 |
| Mosaic 50×50 mm | 2–3 mm | 2.5–4.0 | 4–6 | 3–5 |
Standard Cement-Based Grout
The most common type — suitable for most ceramic and porcelain tiles with joints 2–10 mm wide. Comes unsanded (≤3 mm joints) and sanded (3–10 mm joints). Mix with water to a thick paste. Apply with a rubber float, work diagonally across tiles to pack joints fully. Wipe off excess before it dries.
Epoxy Grout
Two-part resin grout — highly resistant to stains, chemicals, and bacteria. Essential for commercial kitchens, swimming pools, and shower enclosures. More expensive and harder to apply than cement grout but virtually maintenance-free. Work in small sections — it sets fast. Ideal for narrow joints (1–3 mm).
Tile Adhesive Types
Standard adhesive (D1): for wall tiles in dry areas. Flexible adhesive (C2): for floor tiles, large tiles, underfloor heating, or any area subject to movement. Rapid-set (F): for commercial jobs or tiling over existing tiles. Always use flexible adhesive for natural stone, tiles >300mm, or any wet area.
Waterproof Membrane
For wet areas (shower enclosures, wet rooms), apply a tanking membrane or waterproof slurry coat before tiling. One coat is typically applied to the floor and at least 200 mm up the walls. This prevents water penetrating behind tiles, which is the main cause of long-term tile failure in bathrooms.
Tile Laying Patterns & How They Affect Waste
Popular tile patterns, their waste requirements, and when to use each one for best visual effect
Straight Lay (Stack Bond)
The simplest pattern — tiles aligned horizontally and vertically in a grid. Minimum waste (5–10%). Suits large format tiles and minimalist modern spaces. Ensures each tile row is perfectly level and plumb. Start from the centre of the room for a balanced look.
Brick Bond (Offset / Running Bond)
Each row offset by 50% (half the tile width) — like a brick wall pattern. Popular for rectangular tiles, subway tiles, and wood-effect tiles. Creates a subtle movement that makes spaces look wider. Waste: 10–12%. Avoid with large rectified tiles — the offset can make grout lines appear uneven due to lippage.
Diagonal (45-Degree)
Tiles rotated 45° to create a diamond pattern. Visually expands small rooms and adds elegance. Significant extra cuts required at all borders — add 20%+ waste. All cut pieces must be recalculated at 45°. Best executed by an experienced tiler. Suits square tiles and classic ceramic styles.
Herringbone
Rectangular tiles laid in a V-shaped zigzag. Very fashionable for kitchen splashbacks, hallways, and bathroom floors. Adds dynamism and sophistication. Waste: 15–20% due to the many angled cuts. Works best with small-to-medium rectangular tiles (75×300, 100×300, 150×600 mm). Challenging to install — worth hiring a professional.
Windmill Pattern
One large square tile surrounded by four smaller tiles (typically 2:1 ratio). Creates a stylish focal point. Complex to lay and set out. Waste: 15%. Requires two different tile sizes to be calculated and ordered separately. Ensure both sizes are available from the same manufacturer for colour consistency.
Versailles / French Pattern
A combination of four different tile sizes (large, medium, and two small) arranged in a repeating interlocking pattern. Creates a natural, tumbled-stone aesthetic. Very popular for large outdoor areas, conservatories, and Mediterranean-style interiors. Waste: 15–20%. Requires careful pre-planning and setting out.
Tile Calculator — Frequently Asked Questions
Expert answers to the most common tiling questions from DIY enthusiasts and professionals