How Much Flooring Do I Need?
Whether you are installing hardwood, laminate, luxury vinyl plank, tile or carpet, this flooring calculator works out exactly how much material to buy. Enter the room length and width, a waste percentage and, optionally, the coverage per box and price per square foot. It shows the net area, the total with waste, the number of boxes and the total material cost.
Flooring Formula
Net area = length × width. Total with waste = net area × (1 + waste % ÷ 100). Boxes = total with waste ÷ coverage per box, rounded up. Cost = total with waste × price per sq ft.
Example: a 12 ft × 15 ft bedroom is 180 sq ft. With 10% waste you need 198 sq ft. If each box covers 22 sq ft, buy 9 boxes. At $3.50 per sq ft, the material costs about $693.
How Much Waste to Allow
- Simple rectangular rooms with straight-lay planks: 5–10%.
- Rooms with closets, angles or many cuts: 10–15%.
- Diagonal or herringbone patterns and large tiles: 15–20%.
- Keep one spare box after the job for future repairs.
Frequently Asked Questions
How do I measure an L-shaped room?
Split the room into rectangles, calculate each one separately, and add the square footage together. Use the larger waste percentage for the total.
Should I buy all my flooring at once?
Yes. Flooring from different production runs (dye lots) can vary in color and texture. Buying everything at once, including your extra, helps it match.
Does this include underlayment or trim?
No. Underlayment usually matches your floor area, while baseboards and transitions are measured in linear feet around the room. Estimate those separately.