Carpet Calculator
✓ Your estimate
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Sq Feet
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Sq Yards
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+Waste Sq Ft
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+Waste Sq Yds
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Linear Ft of Roll
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Padding Rolls
⚠ This is a planning estimate. Professional carpet installers measure and cut specifically to minimize seams -- their final quote may differ. Confirm quantities with your flooring retailer.
What the Result Means
Carpet is priced by the square yard or square foot depending on your retailer. The linear feet number shows how much carpet needs to come off the roll based on your adjusted area and roll width. For hard-surface alternatives, see the vinyl flooring calculator or tile calculator. All interior tools are at the interior calculators page.
How the Calculation Works
Area (sq ft) = Length x Width + Extra Area
Square Yards = Square Feet / 9
Adjusted Area = Square Feet x (1 + Waste %)
Linear Feet of Roll = Adjusted Sq Ft / Roll Width (ft)
Padding Rolls = Total Sq Ft / Padding Roll Coverage
Roll width affects seam placement -- wider rolls mean fewer seams
Worked Example
Example: 12 ft x 15 ft bedroom, 12 ft roll, 10% waste, padding included
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Area: 12 x 15 = 180 sq ft
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Square yards: 180 / 9 = 20 sq yards
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With 10% waste: 180 x 1.10 = 198 sq ft adjusted
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Adjusted sq yards: 198 / 9 = 22 sq yards
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Linear feet: 198 / 12 = 16.5 linear feet of roll
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Padding (270 sq ft rolls): 180 / 270 = 0.67 -- order 1 roll
Buying Notes
Assumptions Used by This Calculator
- Carpet is sold by the square yard or square foot depending on retailer.
- Roll width affects seam placement and total waste -- wider rolls mean fewer seams.
- Stairs, hallways, closets, and patterned carpet need more waste than this calculator may reflect.
- Professional installers measure to minimize seams -- their cut list may differ from this estimate.
- Padding rolls are calculated from total area without the waste adjustment (padding coverage is simpler).
- This calculator is a planning estimate, not a final installer quote.
Frequently Asked Questions
How do I calculate carpet for a room?
Multiply the room length by the room width to get square feet, then divide by 9 for square yards. Add your waste percentage (typically 10%). For a 12x15 room: 180 sq ft / 9 = 20 sq yards. With 10% waste, order 22 sq yards.
How many square yards are in a room?
Divide the square footage by 9 to convert to square yards. A 12x12 room is 144 sq ft = 16 sq yards. A 12x15 room is 180 sq ft = 20 sq yards. Many carpet retailers price by the square yard.
How much extra carpet should I order?
Order 10% extra for simple rectangular rooms. For L-shaped rooms, rooms with alcoves, stairs, or patterned carpet, add 15-20%. Professional installers add extra to minimize seams in visible areas.
What carpet roll width should I use?
Most residential carpet comes in 12 ft wide rolls. Some premium carpets are available in 13.5 ft or 15 ft widths. A wider roll means fewer seams, which is important for large rooms and visible areas.
Do I need carpet padding?
Yes -- carpet padding extends carpet life, improves comfort underfoot, reduces noise, and helps with insulation. Most carpet manufacturers require padding to maintain warranty coverage.
Should closets be included?
Yes -- closets are part of your installed floor area and need carpet. Include closet square footage in the extra area field. Closets in bedrooms are often carpeted to match the room.
Why does carpet waste vary so much?
Carpet waste depends on room shape, seam placement, roll width, and pattern matching requirements. Patterned carpet can waste 15-25% because cuts must align the pattern across seams. Professional installers measure for minimum seam placement.
Disclaimer: This calculator provides planning estimates only. Actual carpet quantities depend on room shape, seam placement strategy, roll width, and installer method. Always get a professional measurement from your flooring retailer before purchasing. See all interior renovation calculators.