QUICK ANSWER
How much flooring do I need for a 12×15 room?
A 12×15 room is 180 sq ft. With a 10% waste allowance, plan for about 198 sq ft of flooring.
12 × 15 = 180 sq ft · 180 × 1.10 = 198 sq ft
Why add waste?
Cuts, damaged pieces, pattern matching, and layout usually require more material than the exact floor area. The right allowance depends on the product and installation pattern.
Boxes matter
Flooring is normally sold by the box. Divide the adjusted square footage by coverage per box, then round up to a whole box.