Carpet Calculator — Roll Width, Linear Metres, Square Yards & Cost

Real-world use cases

• Sanity-check a fitter's quote before you sign

  A carpet fitter measured your 5 m × 4 m living room and quoted 18.3 m² on a 3.66 m roll. Plug the room in: the tool runs the roll lengthwise (4 m of width needs two 5 m drops = 10 linear m) versus across (5 m of length needs two 4 m drops = 8 linear m) and keeps the 8 m option. With 10% waste that's 8.8 linear m, billed as 8.8 × 3.66 = 32.2 m². If the quote says 32 m² you're fine; if it says 40 m² ask why — either they're running an orientation that wastes roll, or the number is padded.

• Carpet a whole upstairs floor as one order

  You're doing two bedrooms, a landing, and a hallway. Add each as a room with its own length and width — the tool sums the linear metres per room (each picks its own best orientation) rather than treating the floor as one big rectangle, which would under-buy because real rooms don't share off-cuts. One order, one waste factor, one total length to read off to the supplier.

• Convert a US "$28 per square yard" quote to your budget

  A US showroom quotes carpet at $28 per square yard. Switch the tool to imperial, enter the room in feet, set the roll to 12 ft, and pick "yd²" as the billed unit. It converts the billed area to square yards (216 ft² → 24 yd²) and multiplies by $28 → $672. Now you can compare it against a per-square-metre quote from another store without doing the 9-ft²-per-yard conversion in your head.

• Decide between a 3.66 m and a 4 m roll

  Your room is 3.9 m wide. On a 3.66 m roll you seam a 0.24 m fill strip and pay for an extra drop; on a 4 m roll the room fits in a single width with one clean drop. Enter the room once, tap each roll-width preset, and watch the billed area and cost jump between them. The 4 m roll often wins on total cost even at a higher per-metre price because it kills the seam and the off-cut.

• Estimate stair-runner carpet with a higher waste factor

  Stairs eat carpet: every tread and riser is a cut, and the pile must run downhill for wear and looks. Treat the run as a long narrow "room" (total going × width), bump waste to 15% for the cuts and pattern match, and read the linear length. It won't replace a stair template, but it gets you a defensible budget number before the fitter arrives.

Common pitfalls

• Multiplying room area by the price per square metre. Carpet is billed on the full roll width times the linear metres, not on your floor area. A 16 m² room on a 3.66 m roll is billed closer to 18–20 m² once the off-cut is included — budgeting on the floor area alone undershoots every time.

• Comparing a per-square-yard price against a per-square-metre price without converting. A square yard is about 0.836 m² and nine square feet, so "$28/yd²" and "€28/m²" are very different. Pick one billed unit in the tool and convert both quotes into it before you decide.

• Treating several rooms as one big rectangle. Real rooms each force their own seam and off-cut, so the true linear length is the sum of each room's best orientation, not the total area divided by the roll width. Add rooms individually — the tool sums them correctly; a single lumped rectangle under-buys.

• Forgetting pile direction and assuming any orientation is free. Pieces in one room must run the pile the same way, which can force the more wasteful orientation. If your carpet is strongly directional, use the 15% waste preset rather than 5%.

Privacy