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How big a room will my rolls of carpet pad cover?

Carpet cushion comes on a narrower roll than the carpet over it, so it needs its own arithmetic. Enter the rolls you have and the floor they pad comes back at the calculator's roll — 6 by 45 feet, or 1.83 by 13.7 m — with its eight per cent for cuts around closets and doorways taken back off.
  • 2 rollsThe example worked below
  • Carpet Cushion Roll CalculatorEvery figure is its own

You have

How much carpet cushion?

rolls

Worked by the Carpet Cushion Roll Calculator at the settings below.

Saved amounts stay in this browser.

The settings it uses

Cushion Roll Width
6 ft
Cushion Roll Length
45 ft
Cut Allowance (%)
8

What it will do

500 sq ft of carpeted floor

46.5 m²

  1. One room. Enough for a room about 22.4 × 22.4 ft.

  2. Or several. About 1 room of the size the Carpet Cushion Roll Calculator opens on: a room about 21.9 × 21.9 ft.

Check it forwards

Floor Area to Be Cushioned
500 sq ft
It asks for
2 rolls
You have
2 rolls

The Carpet Cushion Roll Calculator asks for 2 rolls at that size, and 3 rolls one step larger.

Open this in the Carpet Cushion Roll Calculator

If you had more, or less

Around your amount

Each worked by the Carpet Cushion Roll Calculator at the same settings.

  1. Half

    1 roll

    250 sq ft

    a room about 15.8 × 15.8 ft

  2. Yours

    2 rolls

    500 sq ft

    a room about 22.4 × 22.4 ft

  3. Half as much again

    3 rolls

    750 sq ft

    a room about 27.4 × 27.4 ft

  4. Double

    4 rolls

    1,000 sq ft

    a room about 32 × 32 ft

Common amounts

What each amount of carpet cushion covers

The sizes it is usually sold in, each worked by the Carpet Cushion Roll Calculator at the settings above.

You haveIt coversAs one roomAverage rooms
1 roll250 sq ft(23.2 m²)a room about 15.8 × 15.8 ftunder 1
2 rolls500 sq ft(46.5 m²)a room about 22.4 × 22.4 ft1
3 rolls750 sq ft(69.7 m²)a room about 27.4 × 27.4 ft1
5 rolls1,250 sq ft(116 m²)a room about 35 × 35 ft2

A roll of pad is not a roll of carpet

Cushion is made narrower than the broadloom above it, so dividing a floor by the carpet's width gives a length of the wrong product. The calculator opens on a 6 by 45 foot roll, 270 square feet (25.1 m²); less its eight per cent, one roll pads about 250 square feet (23.2 m²). Roll lengths vary with density — a denser cushion often comes on a shorter roll — so read both dimensions off the data sheet.

Offcuts can go anywhere

Pad is more forgiving than the carpet over it: there is no pattern to match and no pile direction to keep, so offcuts butt together wherever the carpet seams do not fall. That is why eight per cent is enough in a plain room; a plan broken up by closets, returns and doorways deserves more. Include closets and the floor under furniture, and leave out anything getting a hard surface.

What the rolls leave out

Tack strip, staples or cushion adhesive, and the transition strips at doorways are separate lines. A double-stick commercial installation bonds the cushion down with an adhesive at a rate this count does not compute. The installation standards — CRI 105 for residential carpet and CRI 104 for commercial — govern how cushion is chosen and where its seams fall relative to the carpet above it.

How the answer is worked

Nothing here is a second formula. The Carpet Cushion Roll Calculator runs forwards — a size in, a quantity out — and this page grows its own starting room in proportion until the quantity it asks for is what you have. Where it rounds up to whole containers, the answer is the largest size before the next one would be needed.

Where the calculator adds an allowance for cuts or breakage when you order, the same allowance comes off here, because it is the same calculator: a stack you already own finishes less than its face value. Where it adds none, neither does this page — the settings beside the answer say which.

Carpet Cushion Roll Calculator

runs it forwards

Order the underlay separately from the broadloom: cushion comes on its own narrower roll, so its count never falls out of the carpet order.

Work out what to buy instead

Solve backwards

Other things you might already have

Solve backwards

Start from what is already in the yard

Paint, sheets, rolls, bags and pieces, each read the other way by the calculator that orders it.

Every Solve Backwards pageCarpet Cushion Roll Calculator

  • The calculator's own figures

    Nothing is estimated twice: the page runs the same calculator you would order with.

  • The largest size that fits

    Where a calculator rounds up to whole containers, the answer stops before the next one.

  • Both unit systems

    Gallons and litres, square feet and square metres, side by side.

Frequently asked questions

How much carpeted floor does 2 rolls of carpet cushion cover?
At the Carpet Cushion Roll Calculator's own settings, 500 sq ft (46.5 m²) — a room about 22.4 × 22.4 ft. That is about 1 room of the size the calculator opens on: a room about 21.9 × 21.9 ft. Every figure follows the settings, which you can change in the calculator.
How many square feet is a roll of carpet pad?
It depends on the product. The calculator's default roll is 6 by 45 feet, 270 square feet (25.1 m²), and a metric roll of 1.83 by 13.7 m is about 25 m². Denser cushions often come on shorter rolls for the same handling weight, so use the width and length on the data sheet.
How much carpet pad do I need for a 12 by 12 room?
144 square feet (13.4 m²) plus eight per cent for cuts is about 156 square feet, well inside one 270 square foot roll — the leftover can pad a closet or a hall, since cushion offcuts butt together anywhere. Measure the same floor the carpet was measured from so the two orders agree.
Does carpet pad need as much waste as carpet?
Less. Carpet waste comes from matching a pattern and keeping the pile running one way across seams; cushion has neither, so offcuts are usable almost anywhere. The calculator carries eight per cent for cushion, and more for rooms broken up by closets, returns and doorways.