ContractorHandbook

How Much Flooring for a 20x24 Room?

Boxes to order

24 boxes

480 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 area480 sq ft
  • Coverage per box or carton22.5 sq ft
  • Waste allowance10 %

Boxes to order24 boxes

Floor area480 sq ft
With 10% waste528 sq ft
Boxes at 22.5 sq ft24
Coverage bought540 sq ft
Left over60 sq ftkeep it for repairs

The material list this produces

Flooring, boxes24
Underlayment, sq ft480
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%23 boxes504 sq ft37.5 sq ft
10%24 boxes528 sq ft60 sq ft
15%25 boxes552 sq ft82.5 sq ft
20%26 boxes576 sq ft105 sq ft

What else matters here

Four hundred and eighty square feet plus ten percent is 528, twenty four cartons, 540 bought.

At this size a floating floor may be running into its own limit. Every manufacturer sets a maximum continuous dimension without a break, and the common figures are somewhere around thirty to forty feet in either direction, though plenty of modern vinyl plank goes much further and a few products have no stated limit at all. It is in the installation instruction, and it is a warranty condition rather than advice.

Where the limit is reached, the answer is a T-molding on a proper expansion break, usually at a doorway where it is invisible. That gap is doing the same job as the quarter inch at the walls: giving the field somewhere to go. A continuous run carried past the limit across three rooms is the usual reason a floor peaks in the middle of a hallway in July.

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 20x24 room?

About 24 boxes at 22.5 square feet each, covering 480 square feet with ten percent waste.

How large can a floating floor be without a transition?

It depends on the product. Many set a maximum continuous run around thirty to forty feet, some vinyl plank goes far further, and a few state no limit. Read the installation instruction.

Why do I need a transition between rooms?

To give the floating field an expansion break where its continuous run gets too long. Put it in a doorway where the T-molding is out of sight.

Different numbers?

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

Other common sizes