Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Calculate square yards and how much roll-width material (carpet, turf) you actually need to buy.
1 roll-width strip needed to cover the room's width.
Carpet, artificial turf, and vinyl flooring are usually sold in rolls of a fixed width (commonly 12ft or 15ft), not cut to an arbitrary custom size. This calculator answers a genuinely different question than plain square footage: given your room's dimensions and your material's roll width, how much do you actually have to buy once the roll width doesn't divide evenly into your room?
Enter your room's length and width in feet, and the roll width your chosen material comes in (check with your supplier -- 12ft is the most common carpet roll width in the US, though 15ft rolls also exist). The calculator shows your room's true area alongside the larger area you'll need to purchase.
Strips Needed = ROUNDUP(Room Width ÷ Roll Width)
Material to Buy = Room Length × Strips Needed × Roll Width
If your room is wider than one roll width, you need a whole additional strip to cover the remainder -- you can't buy a fraction of a roll's width. That extra strip is often wider than the leftover room space actually needs, which is why the purchased square yardage is frequently higher than the room's true square yardage.
Use this before ordering carpet, artificial turf, or sheet vinyl for a room, so your purchase quantity (and cost estimate) reflects what you'll actually need to buy, not just the room's true floor area -- which can understate the real material cost if the room's width doesn't divide evenly by the roll width.
This calculator assumes strips run the full length of the room in one direction; real installations sometimes seam differently to minimize visible seams or match a pattern, which can change the actual material needed. For a critical or highly visible installation, confirm the layout plan with your installer before finalizing a purchase quantity.
The roll width can change how much you buy. Take the same 20 foot by 11 foot room with a hypothetical 12 foot roll. The room width of 11 feet fits inside one strip, so you need one strip, and you buy 20 x 1 x 12 divided by 9, or 26.67 square yards. That matches the 4 foot example number, but with far fewer seams. The lesson is that a wider roll can mean fewer seams even when the purchased area is similar, so run the calculator for each roll width your supplier offers.
This calculator runs strips along the length you enter. You can swap length and width to test the other direction. For example, in a room that is 14 feet by 11 feet with a 12 foot roll, running strips along the 14 foot side needs one strip 14 feet long, while running them along the 11 foot side needs two strips. Try both and compare the purchase area and where the seams would land.
The actual area tells you the space, and the purchase area tells you what you pay for. The difference is the leftover that you have to buy. Sometimes you can use leftover pieces for closets, stairs, or a small adjoining room, so it is worth asking your installer about it. If the leftover is large, check whether a different roll width or layout reduces it.
This tool assumes a rectangle. For an L-shaped room, work out each rectangle separately, or ask the supplier to plan the cuts. The Square Footage Calculator can give the true area of complex shapes, but it will not tell you what to buy from a roll.
Multiply the purchase area in square yards by the supplier price per square yard for the material. Remember that padding, installation, tack strips, and delivery are usually priced separately, and prices are quoted by local suppliers, so confirm them directly.
Because carpet comes in fixed-width rolls, and if your room is wider than one roll width, you need a full extra strip to cover the remainder -- even if that remainder is much narrower than the roll itself.
12 feet is the most common roll width for residential carpet in the US, though 15-foot rolls also exist for some products -- always confirm with your specific supplier.
No -- it assumes strips run the length of the room in one direction. A complex layout, pattern-matching requirement, or specific seam placement may need a different material estimate from your installer.
Multiply by 9. For example, 26.67 square yards is about 240 square feet.
Yes. Swapping length and width shows what happens if strips run the other way, which can reduce waste or move seams.
Yes, those areas are not included unless you add them. Ask your installer how much they need for stairs, since it depends on the stair design.