Carpet Calculator
Work out how much broadloom carpet you need from room dimensions and roll width — strips, linear roll length, purchased area, roll-layout waste and simple seams, with both roll directions compared, plus optional padding, tack strip, seam tape, transitions and material cost.
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- Metric & Imperial
Carpet Required
Enter room dimensions to see carpet strips, linear length and purchased area.
How Much Carpet Do I Need?
Room area is:
Room Area = Length × Width
But broadloom carpet often requires more than the room's exact square footage because carpet is sold in fixed-width rolls. The calculator therefore considers room dimensions, roll width, roll direction, strip count, seams and cutting allowance:
Strips = ceil(Coverage Dimension ÷ Roll Width)
Linear Roll Length = Strips × (Strip Length + Cutting Allowance)
Purchased Carpet Area = Roll Width × Linear Roll Length
How Many Square Yards of Carpet Do I Need?
Square Yards = Square Feet ÷ 9
Square yards describe floor area, but the actual broadloom order quantity can be greater because of the fixed roll width and layout. Carpet priced per square yard is costed here on the purchased roll area, not only the room area.
Carpet Roll Width
12-ft broadloom carpet is common, while other widths such as 15 ft and product-specific widths are also available. Always use the actual width for the carpet product — the 12 ft and 15 ft options are convenience values, and a custom width can be entered in feet or meters.
Why Carpet Can Require More Than the Room Area
When a room is wider than the carpet roll, multiple full-width strips may be required. This can create seams, offcuts and additional purchased material. A 15 × 20 ft room with 12-ft carpet needs two strips either way: running along the 20-ft length that is 40 linear ft (480 ft²), while running along the 15-ft width it is 30 linear ft (360 ft²).
The lowest-material orientation is not always the preferred installation layout. Pattern direction, pile direction, lighting, doorways, adjoining rooms, and seam placement may affect the final layout.
The layout waste shown by the calculator is the unavoidable roll-geometry offcut, kept separate from any cutting, pattern or extra allowance you choose.
Patterned Carpet
Patterned carpet can require additional material to align motifs across seams. Pattern repeats vary by product, so use the actual repeat dimensions from the product specifications. Patterned carpet can require additional material so the pattern aligns across seams. Use the repeat dimensions and allowance recommended for the actual carpet product.
No universal pattern allowance is applied — you choose an extra length per strip, a percentage or a custom total.
Estimates, Not Installation Advice
Exact professional seam and cut planning depends on the specific carpet and installation. This calculator estimates material quantity from simple rectangular roll geometry.
Disclaimer: This calculator estimates carpet material from the dimensions and product data you enter. It does not produce a professional seam or cut plan, and it does not determine whether padding, tack strip or seam tape suits your carpet system. Material estimate only. Read full Disclaimer.