Carpet Calculator
Calculate how much carpet you need for any room.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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This calculator converts room dimensions into square yards of carpet and estimates the linear feet you need to cut from the roll, along with padding requirements and an optional cost estimate. Here is how to get an accurate number before you head to the store:
- Measure your room. Enter the length and width in feet. For irregularly shaped rooms, break the floor into rectangles, calculate each section separately, then add the results together.
- Set your waste factor. The default 10% covers pattern matching, cuts at walls, and installation trimming. For rooms with diagonal cuts, patterns that must be aligned, or multiple small pieces, increase this to 15-20%. Simple square rooms with a solid color can use 5-8%.
- Choose your roll width. Most residential carpet is sold in 12-foot wide rolls. Some styles come in 15-foot rolls, which can eliminate seams in wider rooms. The calculator shows you exactly how many linear feet to cut from the roll.
- Enter a price per square foot if you want a cost estimate. Flooring stores typically quote carpet in square yards, so divide their price per yard by 9 to get the per-square-foot rate, or enter it directly if they quote by the foot.
- Review the breakdown. Check the seam information. If your room is wider than the roll, you will need at least one seam. A professional installer can hide seams along a wall or under furniture, but fewer seams always look better.
Results update as you type. Use the Share button to send your measurements to a flooring contractor or store, or Copy to paste the result into a quote request.
About the Carpet Calculator
Carpet is sold by the square yard in the United States, even though rooms are measured in square feet. One square yard equals 9 square feet. A standard 12-foot wide roll means installers measure the room depth (the dimension running parallel to the roll) and cut the needed length. For rooms wider than the roll, two or more strips are seamed together.
Padding, also called carpet cushion or underlayment, is sold separately and covers the same square yardage as the carpet itself. A good padding extends the life of your carpet significantly and improves comfort underfoot. This calculator uses the same square yardage for padding as for carpet. The cost estimate is based on carpet only; budget an additional $0.50-$1.50 per square foot for padding and $1-$3 per square foot for professional installation depending on your area.
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Frequently Asked Questions
How do I convert square feet to square yards for carpet?
Divide the square footage by 9. For example, a 12x10 room is 120 square feet, which equals 120 / 9 = 13.33 square yards. Always round up to the nearest fraction your retailer sells, since you cannot buy a partial square yard. With a 10% waste factor, that same room requires about 14.67 square yards of carpet.
Why do I need more carpet than the room area?
Carpet rolls have a fixed width (usually 12 or 15 feet), so any room dimension that does not divide evenly into the roll width means some material is wasted at the edges. Installers also need extra to trim at walls and door frames, to account for cuts at angles, and to match patterns in patterned carpet. A 10% waste buffer is the industry standard for simple rooms; rooms with alcoves, closets, or repeating patterns often need 15-20% more.
What is the difference between a 12-foot and a 15-foot roll?
The roll width determines how many seams appear on your floor. A 12-foot wide roll works well for rooms up to 12 feet wide with no seam at all. Rooms between 12 and 15 feet wide would need a seam with a 12-foot roll but could be done seamlessly with a 15-foot roll. Wider rolls often cost slightly more per square yard because they are harder to manufacture and ship. If your room is under 12 feet wide, the 12-foot roll is the standard choice. If your room is 13-15 feet wide and you want to avoid a seam, ask your retailer if the carpet style is available in 15-foot width.
Do I need the same amount of padding as carpet?
Yes, padding covers the same area as the carpet. You order padding by the square yard, matching your carpet order. Padding is typically sold in 6-foot or 12-foot wide rolls and cut to fit in the same way as carpet. Budget padding at $0.50-$1.50 per square foot depending on thickness and density. For most residential use, a 7/16-inch thick, 6-pound density cushion is a good balance of comfort and durability. Very plush padding under low-pile carpet can cause premature wear, so check the carpet manufacturer's recommendation.