A 40x40 cm tile covers 0.16 m², so you need 6.25 tiles per square metre. A 12 m² room takes 75 tiles, or 83 with 10% waste.
40x40 Tile Calculator
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About 40x40 Tile Calculator
A 40 by 40 centimetre tile covers 0.16 square metres, so there are 6.25 tiles to the square metre. A 4 by 3 metre room of 12 square metres needs 75 tiles before waste and 83 with a 10 percent allowance. The size is already set on this page, so you only enter the area. Forty by forty sits between the traditional 30 centimetre tile and modern large formats, and it is especially common outdoors on terraces, balconies and around pools. For outdoor use the tile matters more than the size: it needs to be frost resistant porcelain with low water absorption, and it should carry a slip rating suited to wet surfaces. An outdoor floor also has to fall away from the building so water drains, and a 40 centimetre tile follows a gentle fall comfortably where a 60 or 80 centimetre tile would be harder to bed evenly. Indoors, the size suits medium rooms where a 60 centimetre tile would leave thin slivers at the walls. Check the edges before ordering: measure the room against the tile width to see whether the last row will be a usable piece or an awkward strip, and shift the starting line if it is the latter. For a larger format see 60x60 Tile Calculator.
How to use 40x40 Tile Calculator
Choose metric or imperial, then enter the floor, wall or shower dimensions
Enter tile length and width in centimetres or inches
See tile count and optional box count in metric and imperial
Frequently Asked Questions
How many 40x40 tiles per square metre?
Exactly 6.25, since each tile covers 0.16 square metres. Multiply your area by 6.25 and round up, then add the waste allowance.
How many 40x40 tiles for a 20 square metre terrace?
About 125 before waste and 138 with a 10 percent allowance. Outdoor areas with steps, drains or curves usually need a little more.
Are 40x40 tiles good for outdoor use?
The size is well suited to terraces and balconies, but the tile itself must be frost resistant porcelain with a slip rating for wet areas. An indoor tile of the same size can crack after a winter outside.
How do I avoid thin cuts at the walls?
Measure the room width and divide by 40 centimetres to see what is left for the last row. If it is a narrow strip, start from the centre line instead so both sides get an equal, wider cut.
Does a terrace need to slope?
Yes, it should fall away from the building so water drains, typically by 1 to 2 percent. Medium tiles like 40x40 follow that fall more easily than large formats.