Formula
Waste is applied to the square feet, then nine square feet become one square yard:
square yards = length × width × (1 + waste / 100) / 9
The flooring page stays in square feet. This page changes the unit.
Assumptions
- The room is a rectangle in feet.
- The seller prices square yards.
- Waste is a percent of the room.
Worked example
A 12 by 15 foot room with 10% waste needs 22 yd² of carpet.
Input definitions
- Square yard
- Nine square feet. A 9 by 9 foot square is one square yard.
Limitations
Seams, a pattern match, and stairs are not laid out. A seller who rounds up to the next yard may ask for more than this exact figure.
Questions
Why divide by 9?
Each side of a square yard is 3 feet, and 3 times 3 is 9.
What is 12 by 15 before waste?
180 square feet, which is 20 square yards. Ten percent waste makes 22.