Carpet Calculator
Carpet comes in a fixed roll width, so room square footage alone misses the full-width strips and directional offcuts that determine the order.
What does the carpet calculator calculate?
This calculator compares strips running in both room directions and selects the orientation using less full-width carpet. It adds trimming length and an order allowance, then reports linear yards, square yards, strip count, and pad area. Final seam placement must be approved by the installer.
Carpet roll-strip formula
The calculator tests both room orientations because every strip consumes the full roll width. It chooses the lower linear-foot result, adds trim and allowance, then converts roll length to yards.
How to measure for an accurate estimate
- Measure the room at the widest and longest points, including doorway recesses and carpeted closets.
- Confirm the carpet’s actual roll width; common widths exist, but product dimensions are not universal.
- Measure connected rooms separately when a doorway or pile-direction rule affects seam placement.
- For patterned carpet, obtain the exact length and width pattern repeat before the installer prepares a seaming plan.
Carpet for a 15-by-13-foot room
A 15-by-13-foot room uses 12-foot-wide carpet, six inches of trim per strip, and a 5% additional allowance.
Two strips running along the 13-foot side use less carpet: about 9.45 linear yards, 37.8 square yards, plus 22.75 square yards of pad.Before you purchase material
- Have an experienced installer approve seam locations before ordering, especially in doorways and high-traffic paths.
- Keep pile direction consistent across visible connected areas even if another orientation uses less material.
- Select pad density and thickness allowed by the carpet manufacturer and warranty.
- Order patterned products only after accounting for pattern matching, bow, skew, and roll sequence.
Common questions
Why is carpet ordered in linear yards?
Carpet is manufactured as a roll with a fixed width, so the purchase length determines total material. One linear yard is three feet of the full roll width. Square-yard pricing must still account for strips, seams, and offcuts.
Does carpet direction matter when measuring?
Yes. Carpet pile normally needs one consistent direction, and patterned products require aligned repeats. The mathematically smaller orientation may create unacceptable seams or reversed pile. An installer should approve direction and seam layout before the final order.
How much carpet padding should I order?
Pad generally follows the actual floor area rather than full carpet roll strips, so it creates less offcut waste. Adding about 5% is a useful planning allowance for a simple room. Stairs, unusual shapes, and package sizes may require more.
Can this carpet calculator estimate stairs?
No. Stairs require tread depth, riser height, width, nosing wrap, installation method, pile direction, and pattern matching. Measure every stair component and ask the installer or carpet supplier to prepare a stair-specific cut and seam plan.
Sources and reference standards
- Carpet and Rug InstituteIndustry consumer guidance for carpet selection, installation, and maintenance.