Tile Calculator — How Many Tiles Do I Need?
Enter your room dimensions and tile size to calculate exactly how many tiles to order, including waste allowance for cuts.
How many tiles do I need?
Measure room length x width to get the area in m². Divide by the individual tile area, including grout gap, to get the base tile count. Always add at least 10% for waste and cuts.
How much waste should I allow for tiles?
Use 10% for straight lay in a simple rectangle. Use 15% for diagonal 45° lay because angled cuts waste more. Use 15% for rooms with obstacles such as a bath, toilet or kitchen units, and 20% for herringbone or complex patterns.
What is a grout gap and does it affect tile count?
The grout gap adds to the effective size of each tile. A 600mm tile with a 3mm grout gap takes up 603mm of space. For large rooms this makes a measurable difference, which is why the calculator includes the grout gap in its calculation.
How to measure a room for tiling
Measure the longest length and widest width, including any alcoves. For L-shaped rooms, split into two rectangles, run the calculator for each, and add the tile counts together.
Tile calculator for floors vs walls
For floors, use the full room area. For walls, measure each wall separately as width x height and subtract doors and windows. Run the calculator once per wall and add the totals.
How many tiles come in a box?
Every box shows the tile count and coverage in m² on the label. Enter the tiles per box figure into the calculator to get your exact box count and avoid ordering the wrong amount.
Also useful:
Carpet calculator · Calculator for sq feet · Main calculator
Tile calculator FAQ
Frequently Asked Questions
How do I calculate how many tiles I need?
Measure your room length x width to get the area in m². Divide by the tile area including grout gap to get the base tile count, then add 10% for waste. For example, a 3m x 4m room is 12m². With 600x600mm tiles and 3mm grout each tile covers 0.363m², giving 34 base tiles plus 10% waste = 38 tiles.
How much extra tile should I buy for waste?
Buy 10% extra for straight lay in a simple room. Buy 15% extra for diagonal lay, patterned tiles, or rooms with lots of obstacles. Buy 20% extra for herringbone or complex patterns.
How many 600x600 tiles do I need for 10m²?
With a 3mm grout gap, each 600x600mm tile covers 0.363m². For 10m² you need 28 base tiles plus 10% waste = 31 tiles. Check your box coverage in m² to convert to a box count.
Should I include the grout gap in my tile calculation?
Yes - the calculator does this automatically. A 3mm grout gap adds 3mm to each tile dimension, which affects how many tiles fit across the room and the total tile count.