How this flooring calculator works
The calculator multiplies room length by width, adds a waste allowance for end cuts and mistakes, and divides by the coverage printed on your flooring's box to get a box count, rounded up. Box coverage varies by product — laminate boxes are commonly around 20 sq ft (1.9 m²), vinyl plank 20–24 sq ft, and hardwood bundles anywhere from 18 to 25 — so check your specific product.
How much waste to allow
8% is a sensible default for straight-lay plank in a simple rectangular room. Go to 10–12% for rooms with closets, alcoves and angles, and 15% for diagonal or herringbone layouts. Wide rooms relative to plank length waste less; narrow halls waste more. Always keep a leftover box — a matching repair plank years later is worth far more than the refund.
Irregular rooms
Split L-shaped or complex rooms into rectangles, calculate each, and add them together before applying waste. For rooms with angled walls, measure at the widest points — it's cheaper to have offcuts than to come up one row short with a discontinued color.
What else to budget
Underlayment covers the same area as the flooring (some vinyl and laminate has it pre-attached — check). Add transition strips at doorways, quarter-round or new baseboards at the walls, and for floating floors leave the expansion gap the manufacturer specifies, typically ¼–⅜ inch (6–10 mm) at every wall.