ContractorHandbook

How Much Flooring for a 15x15 Room?

Boxes to order

11 boxes

225 square feet of floor, ten percent waste, boxes of 22.5 square feet.

It does not stop at a number.

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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.

How that number is worked out

These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.

  • Floor area225 sq ft
  • Coverage per box or carton22.5 sq ft
  • Waste allowance10 %

Boxes to order11 boxes

Floor area225 sq ft
With 10% waste247.5 sq ft
Boxes at 22.5 sq ft11
Coverage bought247.5 sq ft
Left over22.5 sq ftkeep it for repairs

The material list this produces

Flooring, boxes11
Underlayment, sq ft225
Transition strips, each2

Waste allowance compared

Waste is set by how you lay it, not by how careful you are. Straight lay to herringbone, same room.

Waste allowanceBoxes to orderWith 10% wasteLeft over
5%11 boxes236.3 sq ft22.5 sq ft
10%11 boxes247.5 sq ft22.5 sq ft
15%12 boxes258.8 sq ft45 sq ft
20%12 boxes270 sq ft45 sq ft

What else matters here

Two hundred and twenty five square feet with ten percent waste is 247.5, which happens to be exactly eleven cartons at 22.5 square feet. That is a rare clean landing and it means there is no hidden rounding cushion in the order, so any extra waste comes straight out of the spare.

If the room has a closet, an alcove or a bay, add that area separately rather than assuming the waste covers it. Waste allowance covers offcuts, not additional floor.

Fifteen feet across is wide enough that the first row has to be dead straight or the error compounds all the way over. Snap a chalk line off the longest wall rather than trusting the wall itself, because almost no wall is straight over fifteen feet.

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.

Questions people ask

How many boxes of flooring for a 15x15 room?

About 11 boxes at 22.5 square feet each, covering 225 square feet with a ten percent waste allowance.

Should I add extra for a closet?

Yes. Measure the closet floor and add it to the room area rather than hoping the waste allowance covers it, because waste covers offcuts, not extra floor.

How do I keep the first row straight?

Snap a chalk line rather than working off the wall. Walls are rarely straight, and a first row that follows a bowed wall puts a growing wedge into every row after it.

Different numbers?

The flooring calculator takes any dimensions you like and hands back the same list.

Other common sizes