ContractorHandbook

Flooring and Tile Calculator: Boxes to Order

Area plus waste divided by box coverage, rounded up, because you cannot buy two thirds of a carton. The waste percentage is where the judgment lives, and the lay pattern decides it.

It does not stop at a number.

When the figures look right, the flooring material list downloads as a real PDF with your business details on it, built inside your own browser. Nothing you type is uploaded anywhere.

waste10%room area, sq ftone box covers a fixed number of square feetarea with waste / coverage per box = boxes, rounded up
Flooring is sold by the box and installed by the plank, so the only number that matters on the label is the square feet per box. The waste allowance covers the cut at each wall and the offcut that starts the next row.

Worked example

These are the figures the calculator opens with and the answer it gives. Change anything above and every number below moves with it.

  • Floor area420 sq ft
  • Coverage per box or carton22.5 sq ft
  • Waste allowance10 %

Boxes to order21 boxes

Floor area420 sq ft
With 10% waste462 sq ft
Boxes at 22.5 sq ft21
Coverage bought472.5 sq ft
Left over52.5 sq ftkeep it for repairs

The material list this produces

Flooring, boxes21
Underlayment, sq ft420
Transition strips, each2

What this calculator assumes

  • 10 percent waste covers a straight lay in a simple rectangle. Go to 15 for a diagonal or herringbone lay, and 20 if the room is cut up with closets and angles.
  • Buy the whole job in one delivery. Dye lot and batch shade move between production runs, and a single replacement box six months later will not match.

The waste percentage is the whole decision

Ten percent covers a straight lay in a plain rectangular room. Fifteen is right for a diagonal lay, because every cut at the wall is a diagonal and the offcut rarely serves anywhere else. Twenty is not excessive for herringbone, chevron, or a floor plan cut up with closets, angles and transitions.

Long planks in a small room waste more than short planks in a big one, because the offcut at the end of a run has nowhere to go. Tile with a strong pattern match wastes more than tile without.

Buy it all at once, this one is not negotiable

Flooring is manufactured in batches, called dye lots for carpet and shade or batch numbers for tile and LVP. Two boxes of the same product from different runs can be visibly different under a window, and there is no fixing it after installation.

Order the whole job, including the attic stock, in one delivery, and check the batch number on every pallet before the truck leaves. Keep the leftover, labeled, in the crawlspace. In four years when a fridge line leaks, that box is the difference between a patch and a new floor.

Questions people ask

How many boxes of flooring do I need for 500 square feet?

At 10 percent waste that is 550 square feet. Divide by your box coverage, so at 22.5 sq ft a box you need 25 boxes, which buys 562.5 square feet.

Why does dye lot matter?

Dye lot and batch shade move between production runs, and a single replacement box six months later will not match.

Need the paperwork too?

Flooring estimate template and Flooring invoice template, free, no signup, PDF Word and Excel.

Common sizes, worked out

The same calculator with the numbers already filled in, one page per size, each ending in its own material list.

More sizes, answered

Each row is this calculator run with those numbers when the page was built. Type the same numbers in above to see every line of the working.

ExampleWhat it assumesBoxes to order
10x10 room100 square feet of floor, ten percent waste, boxes of 22.5 square feet.5 boxes
11x12 room132 square feet of floor, ten percent waste, boxes of 22.5 square feet.7 boxes
10x14 room140 square feet of floor, ten percent waste, boxes of 22.5 square feet.7 boxes
12x14 room168 square feet of floor, ten percent waste, boxes of 22.5 square feet.9 boxes
12x15 room180 square feet of floor, ten percent waste, boxes of 22.5 square feet.9 boxes
12x16 room192 square feet of floor, ten percent waste, boxes of 22.5 square feet.10 boxes
14x14 room196 square feet of floor, ten percent waste, boxes of 22.5 square feet.10 boxes
200 sq ft200 square feet of floor, ten percent waste, boxes of 22.5 square feet.10 boxes
12x18 room216 square feet of floor, ten percent waste, boxes of 22.5 square feet.11 boxes
12x20 room240 square feet of floor, ten percent waste, boxes of 22.5 square feet.12 boxes
250 sq ft250 square feet of floor, ten percent waste, boxes of 22.5 square feet.13 boxes
16x16 room256 square feet of floor, ten percent waste, boxes of 22.5 square feet.13 boxes
300 sq ft300 square feet of floor, ten percent waste, boxes of 22.5 square feet.15 boxes
16x20 room320 square feet of floor, ten percent waste, boxes of 22.5 square feet.16 boxes
18x18 room324 square feet of floor, ten percent waste, boxes of 22.5 square feet.16 boxes
20x20 room400 square feet of floor, ten percent waste, boxes of 22.5 square feet.20 boxes
20x24 room480 square feet of floor, ten percent waste, boxes of 22.5 square feet.24 boxes
20x30 room600 square feet of floor, ten percent waste, boxes of 22.5 square feet.30 boxes
700 sq ft700 square feet of floor, ten percent waste, boxes of 22.5 square feet.35 boxes
800 sq ft800 square feet of floor, ten percent waste, boxes of 22.5 square feet.40 boxes
1,500 sq ft1,500 square feet of floor, ten percent waste, boxes of 22.5 square feet.74 boxes
2,500 sq ft2,500 square feet of floor, ten percent waste, boxes of 22.5 square feet.123 boxes

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