CalcArcade.

Flooring Calculator

Enter the room as a length and width, or as a floor area. Add a waste allowance and the coverage of one box. You get the area to buy and the number of boxes.

Your numbers

Result

How we calculate it

The area to buy is the floor area times (1 + waste ÷ 100). The number of boxes is the area to buy divided by the coverage of one box, rounded up to a whole box. The extra area is what the boxes cover beyond what you need.

For a 12 by 15 foot room (180 square feet) with 10% waste, you need to buy 198 square feet. If a box covers 20 square feet, that is 9.9 boxes, so you buy 10 and have 2 square feet to spare.

Assumptions and limits

  • Waste depends on the layout and the room. 10% is a common allowance, and diagonal layouts or patterned boards need more.
  • Measure the longest length and widest width of each room, and add rooms together if you are flooring more than one.
  • Check the coverage printed on the box. It can differ between products of the same size.

Frequently asked questions

How much extra flooring should I buy?

Most people add about 10% for cuts, mistakes and future repairs. Add more for diagonal layouts, tricky rooms or a pattern that has to be matched.

How do I measure a room for flooring?

Measure the length and width in the same unit and multiply them. For an L shaped room, split it into rectangles, work out each one and add the areas.

Why does the calculator round the boxes up?

Flooring is sold in whole boxes, and buying one box too few would leave the job unfinished. The extra area shows what you will have left.

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Worked example (a fixed example using the starting numbers, it does not change as you type)

Inputs: Enter the room as = Length and width; Units = US (feet and inches); Room length (feet or meters) = 12; Room width (feet or meters) = 15; Waste and cuts (%) = 10; Coverage per box (square feet or square meters, optional) = 20.

  • Floor area 180.00 sq ft
  • Area to buy (with waste) 198.00 sq ft
  • Boxes needed 10
  • Extra area covered 2.00 sq ft

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Last reviewed: . Formulas and assumptions are described on our methodology page. For information only; not professional advice.