Tile Calculator
Calculate how many tiles you need for a room or wall — including waste and boxes required.
How it works
- 1Enter your room or wall length and width in metres or feet.
- 2Choose your tile size and set a waste percentage (10% for straight layouts, 15% for diagonal).
- 3The calculator divides the area by the tile area, applies waste, then rounds up to whole boxes.
Use cases
- Estimating tile quantities before visiting a builder’s merchant.
- Comparing how tile size affects the number of boxes needed.
- Planning bathroom, kitchen, or outdoor paving projects.
Frequently asked questions
How is the tile count calculated?
Tiles = ⌈(room area ÷ tile area) × (1 + waste ÷ 100)⌉. A 4 m × 3 m room (12 m²) with 300×300 mm tiles (0.09 m²) at 10% waste needs ⌈(12 ÷ 0.09) × 1.10⌉ = 147 tiles.
How much waste should I add?
Add 10% for straight grid layouts and 15% for diagonal or herringbone patterns. Add an extra 5% for large natural-stone tiles where colour matching matters.
Why do I need to buy whole boxes?
Tiles are sold in fixed-quantity boxes. The calculator rounds up to the nearest full box so you always have enough — leftovers are useful for future repairs.
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