Understanding your result
The headline is the pieces to order, with the pattern and the waste used beneath it. The stats show the waste, the number of cut pieces round the walls and the pieces before waste; the table adds the waste caused by the cuts and the starting line.
Cut pieces at the walls are estimated from the room’s perimeter. In a diagonal grid a piece meets the wall roughly every diagonal of a piece; in herringbone and chevron, every half-diagonal of a piece’s length, because pairs of pieces meet the wall in a V. Each cut piece wastes roughly half its area. Waste from the cuts is that total as a share of the floor. Waste used is the larger of that figure and the rule of thumb, 15% for a diagonal and 20% for herringbone, so a small or narrow room gets the higher figure it needs.
The starting line is the thing to get right on the day. For a diagonal, two lines at 45° through the centre of the room; for herringbone and chevron, one centre line along the room. For the boxes, take the pieces or the area and this waste to the boxes and cartons calculator; for straight layouts, the tile layout calculator and the plank layout calculator work out the cut widths instead.
How we calculate this
The cut estimate is an approximation from geometry, not a layout: it assumes cut pieces are on average half wasted, which is a fair average across the triangles and trapezoids a 45° edge produces. Chevron wastes slightly less because the angle at the ends is cut in the factory. The rules of thumb come from the waste factors reference. The waste guide explains why pattern floors waste more, the plank direction guide covers where the eye goes in a room, and the large-format tile guide covers diagonal layouts of big tiles.
The assumptions behind the numbers
| Assumption | Default | Where it comes from |
|---|---|---|
| Piece | 24 × 4 in | A common herringbone plank and tile size |
| Rules of thumb | 15% diagonal, 20% herringbone and chevron | Manufacturer estimating guidance |
| Cut waste | half of each cut piece (chevron 40%) | Geometric average of 45° cuts |
| Room | 14 × 12 ft (4.2 × 3.6 m) | A typical living room |
Assumptions last reviewed October 8, 2026.
The calculator treats the room as a rectangle and estimates the cuts from its perimeter; an island, a fireplace or a bay adds more cuts than the perimeter of a rectangle shows. It does not draw the layout or position the pattern relative to the door, and it does not handle a herringbone with a border, which adds a straight frame of pieces round the room; count the border separately as a straight layout.
Two worked examples
An 18 × 13 ft dining room in herringbone
24 × 4 in pieces.
- Floor: 234 sq ft; pieces before waste 234 ÷ 0.667 = 351
- Cut pieces: 62 ft of wall ÷ 1.41 ft = about 44; cut waste 44 × 0.333 = 15 sq ft = 6.3%
- Waste used: the 20% rule, which is higher; pieces 422
In a room of ordinary proportions the rule of thumb is the larger figure, and the cuts alone would understate the waste: herringbone also loses pieces to defects, to the first rows and to the A/B balance coming out uneven.
A 10 × 8 ft entry in 12 in tile on the diagonal
- Floor: 80 sq ft; tiles before waste 80
- Cut pieces: 36 ft of wall ÷ 1.41 ft = about 26; cut waste 13 sq ft = 16.3%
- Waste used: 16.3%, above the 15% rule; tiles 93
A small room has more wall per square foot, so the cuts alone exceed the rule. In a hallway the effect is stronger still; this is the case the calculator exists for.
Where to find your inputs
Room. Wall to wall at floor level; for an L-shape, run each rectangle separately.
Piece size. From the product page; herringbone pieces are usually listed by length and width.
Pattern. Diagonal for a 45° grid of tiles or planks; herringbone for rectangular pieces at right angles; chevron for pieces with angled ends.
Common mistakes
- Using 10% for a pattern floor. Diagonal starts at 15%, herringbone at 20%.
- Ordering herringbone as one kind of piece. It comes in left and right pieces, in equal numbers.
- Starting at a wall. Pattern floors start from a centre line.
- Ignoring a small room. Small rooms waste more per square foot; the calculator accounts for it.
- Random-length wood for herringbone. Use pieces made for the pattern.
- Forgetting a border. A straight border round a herringbone field is counted separately.
Questions people ask
- How much extra flooring for herringbone?
- Plan on at least 20% over the floor area. Every row ends at the wall in an angled cut, and the offcuts rarely fit elsewhere. In a narrow room or a hallway the cuts can push the real waste to 25 or 30%; the calculator estimates it from the room.
- How many herringbone pieces do I need?
- Divide the floor area by the area of one piece and add the waste. A 14 × 12 ft room in 24 × 4 inch pieces is 252 pieces before waste and 303 with 20%. Order them in left-hand and right-hand pairs.
- What is the difference between herringbone and chevron?
- Herringbone pieces are rectangles laid at 90° to each other, so the end of one butts the side of the next. Chevron pieces have their ends cut at an angle so they meet in a point. Chevron pieces arrive with the angle factory-cut, which slightly reduces site waste.
- Where do I start a herringbone floor?
- On a centre line snapped down the length of the room, usually the line people see first from the doorway. Lay the first pieces along that line and work toward both long walls, so the cuts at each wall are equal.
- How much waste for a diagonal tile floor?
- About 15% in an average room, more in a small one. A 10 × 8 ft room in 12 inch tile on the diagonal has about 26 cut pieces round the walls, which is about 16% of the floor; the calculator uses that rather than the 15% rule.
- Do I need special flooring for herringbone?
- For wood, usually yes. Herringbone pieces are sold as fixed-length left and right pieces with tongues on the right sides. Ordinary random-length planks would need every piece cut and machined. Tile and vinyl herringbone use rectangular pieces sold for the purpose.