Nine square feet make one square yard.
Room area is length times width. Divide by 9 for square yards. Waste multiplies that quantity. Ten percent is the starting waste for a simple room. Seams, stairs, and a pattern match often need more, so the field is editable. Cost is the order quantity times the price you type. Pad, tack strip, and labor are not in the price. The vinyl setting skips the yard conversion and prices the square feet after waste. It is the same area math with a different selling unit.