CalculatorAsphalt

Carpet Calculator

Carpet in square yards from room size, with roll-width seam waste.

Quick answer: Carpet sells by the square yard (area ÷ 9) but comes on 12 ft rolls — rooms wider than 12 ft need seams and extra length. Plan 10% over for pattern match and seams.

How to use this calculator

  1. Enter Room length in ft.
  2. Enter Room width in ft.
  3. Press Calculate. The highlighted row is your order quantity; the note beneath it translates the number into real-world terms.

Formula & constants

Carpet sells by the square yard (area ÷ 9) but comes on 12 ft rolls — rooms wider than 12 ft need seams and extra length. Plan 10% over for pattern match and seams. Every default in the fields above is editable — when your supplier’s spec sheet lists a different density, coverage rate or price, enter that number instead. The waste and compaction allowances follow common trade practice; see our methodology page for the derivation of each formula and the standards it references.

Worked example. With room length = 10 ft, room width = 10 ft, the calculator returns:
Area100 sq ft
Square yards12.2 sq yd
Pad needed100 sq ft

Where this fits in the project

Interior finishing runs framing-out: studs, insulation, drywall, then paint and floor coverings. Measure once and reuse the same wall and floor areas across each material takeoff.

How this connects to your project

No quantity stands alone — each material in the chain depends on the ones around it. These are the planning steps that pair with the carpet calculator:

Frequently asked questions

Why is carpet priced per square yard?

Industry convention from roll goods — divide sq ft by 9. Rolls are 12 ft wide, which drives seam planning.

Do I need new pad with new carpet?

Almost always — old pad is compressed and voids most carpet warranties if reused.

Last verified: — prices reflect current national averages. See our methodology.

Estimates are for planning. Material densities, coverage rates and prices vary by region and supplier — confirm final quantities before ordering, and check local code where structural or electrical work is involved.