How to use this calculator
Enter the room and the tile. For a classic herringbone use a 2:1 tile — 3 by 6, 4 by 8, 6 by 12, 8 by 16. If your tile is not 2:1 the calculator will lay it as a double or triple herringbone, which is the correct way to handle a 4 by 12 or a 7 by 48 plank, and it will tell you underneath the plan what it did.
Set the grout joint before you read the grout line. On small herringbone tile the joint width changes the grout order by a factor of four. It does not move the tile count: the calculator counts tile at the size on the box.
Why herringbone wastes 17% and up
In a grid layout a perimeter tile is cut once, straight, and the offcut is often usable on the opposite wall. In herringbone every tile meets the wall at 45 degrees, so each perimeter piece takes two cuts, and the offcut is a triangle with two wrong angles.
The arithmetic is unforgiving. A 12 by 14 room has 52 linear feet of perimeter. With a 6 by 12 tile at 45 degrees the plan cuts 89 perimeter pieces, each one a double cut, each one throwing away between a third and two thirds of a tile. That is where the 17% comes from, and it is why a small bathroom in herringbone can hit 20%.
A room with a bump-out, an island or an angled wall pushes it higher still. The plan measures it for your actual room rather than quoting a table, and shows the larger of the two numbers. The comparison across every layout is in tile waste factor by pattern.
Single vs double herringbone
A single herringbone uses one plank per leg of the V. It only closes geometrically when the plank is exactly twice as long as it is wide, which is why herringbone tile is sold in 2:1 ratios.
A double herringbone uses two planks side by side as one leg. A 4 by 12 plank is 3:1 and will not close on its own; two 4 by 12 planks together are 8 by 12, which is close enough to be trimmed to a 2:1 unit. A 7 by 48 plank needs three side by side. The calculator picks the number of planks per unit for you, cuts them to length in the plan, and counts the trim as waste — because it is.
Double herringbone also reads differently on the floor: a bigger, calmer pattern that suits a large open room, where a single herringbone in small tile can look busy.
Starting point and the centre line
Herringbone is laid from the middle of the room, always. Snap two chalk lines through the centre at 90 degrees, then snap a third at 45 degrees through the intersection. That third line is the spine of the pattern and every tile references it.
Dry-lay the first eight to ten tiles along the spine before any thinset goes down. Check that the cuts at opposite walls are roughly equal and that no wall ends with a sliver. If they are uneven, slide the whole spine — not the individual tiles — until they balance. The general method is in how to lay out a tile floor; herringbone just punishes you harder for skipping it.
One more practical point: mark the spine on the subfloor with a pencil as well as chalk. Chalk lines disappear the moment you trowel over them, and by the third row the pattern will have drifted a quarter inch if you have nothing left to check against.
Budget for the consumables a herringbone eats that a grid does not. You will get through two or three diamond blades on a 150 square foot floor because every cut is a mitre and the blade is working on a corner rather than a face; a decent 7 inch continuous rim blade is $35 to $60. Levelling clips are worth budgeting for as well, because the small tiles a herringbone usually uses put a lot of joint into every square foot. Clips run about $25 per 100, and a 150 square foot herringbone floor takes 400 to 500 of them.
Common mistakes
- Ordering with a 10% waste factor. That is the grid number. Herringbone starts at 17% and the plan will tell you when your room needs more.
- Using a non-2:1 tile without planning for it. A 4 by 12 in single herringbone leaves gaps that no grout joint can absorb. Lay it double.
- Starting at a wall. The pattern will run out of square within six feet and there is no way back.
- Cutting at 45 degrees with a hand-held blade. Herringbone needs a wet saw with a working mitre fence. Free-handing the perimeter is what turns 17% waste into 25%.
- Underestimating the labour. Expect a setter to charge more per square foot for herringbone than for a straight lay — 30% to 50% more is this site’s rough guide. If you are hiring, get the rate in writing before the tile arrives.