The four floor tile patterns
Straight lay (grid). Tiles sit in a square grid with aligned grout lines. It is the fastest to install, wastes the least at 10 percent, and makes small rooms feel larger because the eye follows the straight lines. Best for most floors and the default choice unless you have a reason to do otherwise.
Diagonal. The same grid rotated 45 degrees. It adds movement to plain rooms and hides out-of-square walls, because the angled lines do not run parallel to any wall. The cost is 15 percent waste: nearly every tile along the walls gets cut twice, and the triangular offcuts rarely fit anywhere else.
Brick offset (subway pattern). Each row shifts by half a tile, like brickwork. It suits rectangular tile and adds rhythm without the cost of a diagonal. Use the standard 10 percent waste, but read the one-third rule below before offsetting large format tile by a full half.
Herringbone. Rectangles interlock at 90 degrees in a zigzag that reads as woven texture. It is the showpiece pattern, and it wastes the most: plan 20 percent. Almost every perimeter tile is a custom cut, and the offcuts fit nowhere. A 150 square foot room with 6 by 12 inch tile (0.5 square feet each) needs 300 tiles before waste, and 300 times 1.20 is 360 tiles to buy.
Where to start laying floor tile
Start at the center of the room, not at a wall. Find the center by snapping a chalk line between the midpoints of opposite walls, then snap a second line perpendicular to it. Walls are rarely straight and almost never square, so starting at a wall copies the wall's error across the entire floor. Center lines split the difference: cut tiles on opposite walls come out the same width, and the room reads as symmetrical.
Before mixing any thinset, dry lay one row of tiles with spacers along each chalk line, all the way to the walls. If the last tile at either wall would be a sliver under half a tile wide, shift the whole line by half a tile and dry lay again. Slivers look bad and break easily; ten minutes of dry laying prevents a floor full of them. Work outward from the center in quadrants once the layout is set.
The 3-4-5 rule: squaring your lines
Chalk lines are only useful if they are square. The 3-4-5 rule checks that with a tape measure: from a corner, mark 3 feet along one wall and 4 feet along the adjacent wall. Measure the diagonal between the two marks. If it is exactly 5 feet, the corner is square. If it is more or less, adjust the lines until the diagonal reads 5 feet.
Do this for every room before you lay a tile. A grid that starts one degree off square drifts visibly across a 15 foot room, and by the far wall your grout lines will visibly converge. The rule takes two minutes and a helper holding the tape.
The 1/3 rule for large format tile
Large tiles, 12 by 24 and bigger, bow slightly across their length from the firing process. In a half offset (brick pattern), the crowned middle of one tile lands against the flat ends of its neighbors, and the height difference shows as lippage, an edge you can feel underfoot. The fix is the one-third rule: offset large format tiles by one third of their length instead of one half.
The one-third stagger breaks up the alignment enough to look intentional while keeping the high and low points of adjacent tiles close together. Many manufacturers now require a maximum one-third offset in their installation specs, so this rule also keeps your warranty intact.
Matching waste factor to pattern when ordering
Order with the pattern's waste factor, not the generic 10 percent, or you will run short on the last day. Straight and brick offset: 10 percent. Diagonal: 15 percent. Herringbone and chevron: 20 percent. Rooms with many jogs, closets, and doorways push each number up a little; clean rectangles let you hold the line.
Once you know your pattern and area, the tile calculator applies the waste allowance and converts to boxes. Pick the allowance that matches your pattern in the waste dropdown: straight lay for the grid, diagonal or patterned for everything angled.