About This Calculator
Carpet is priced and sold by the square yard (1 yd² = 9 sq ft), unlike hard flooring which is sold by the square foot or box. This calculator converts your room dimensions to square yards and adds a waste allowance for cuts, seams, and pattern matching.
How much waste should I add?
For simple rectangular rooms with no pattern: 5–10%. For rooms with angles, stairs, or a carpet with a pattern repeat: 15–20%. It's better to buy slightly more — carpet dye lots vary and you won't be able to match later.
Carpet installation tips
- Always buy from the same dye lot for consistent color.
- Carpet is typically sold in 12-foot-wide rolls — if your room is wider, you'll need a seam.
- Add padding to your budget: expect $0.50–$1.50/sq ft for quality carpet padding.
Frequently asked questions
How does this carpet calculator work?
Enter each room's length and width in feet. The carpet calculator adds up the total floor area, applies the waste percentage you choose, and converts the result to square yards — the unit most carpet is sold in.
How much extra carpet should I buy for waste?
Most installers add 10% for simple rectangular rooms and 15–20% for rooms with lots of corners, closets, stairs, or patterned carpet that has to be matched. The 10% default is a safe starting point.
Why is carpet measured in square yards?
Carpet is manufactured and priced by the square yard in the US, where 1 square yard equals 9 square feet. This tool shows both units so you can compare quotes and order the right amount.
Methodology & sources
How this calculator works: it multiplies your room dimensions to get the floor area, adds your chosen waste allowance (5–20% for offcuts, pattern match and seams), then divides by 9 to convert square feet to square yards — the unit carpet is often priced in. Bought-quantity is rounded up. Sources: square-foot to square-yard conversion is exact (1 yd² = 9 ft²); waste ranges follow common flooring-installer practice. Estimates are for planning only. Last reviewed: by the Toolchive Team.