About & methodology

Carpet Calculator is a free tool that estimates how much carpet a room needs and what it costs installed, from the room size. No sign-up; the math runs in your browser.

How it works

• Floor area = length × width; square yards = area ÷ 9 (carpet is priced per square yard).
• Carpet is cut from a fixed-width roll (12 ft standard, also 13.5 and 15 ft). We lay the roll down the longer side to minimize seams.
• A room wider than the roll on its short side needs ceil(short ÷ roll width) strips — each strip runs the room length, so extra roll goes to waste at the seams.
• Purchased area = roll width × total running length; waste % = (purchased − floor) ÷ floor.
• Cost = carpet (purchased sq yd × grade price) + padding (floor sq ft × pad price) + installation (purchased sq yd × labor rate), each as a low–high range.

Default rates

Carpet $20–$80/sq yd by grade, padding $0.30–$1.50/sq ft, installation $15–$35/sq yd — mid-2020s US ranges. These are planning estimates; stairs, tack strip, furniture moving, and old-carpet removal cost extra. Get quotes for your job.