GRLab

Flooring Calculator

How much flooring do I need? Get square footage with waste, boxes to buy, and cost.

Waste: 10% straight lay · 15% diagonal or herringbone · 20% complex rooms.

Estimates only. Check the coverage printed on your product's box, and confirm waste needs for your layout before ordering.

How to calculate how much flooring you need

  1. Measure the floor area. For a rectangular room, multiply length by width. For L-shaped or irregular rooms, split the floor into rectangles, calculate each, and add them together (use the "By total area" mode).
  2. Add a waste factor. Every job loses material to end-of-row cuts, mistakes, and damaged planks. 10% is standard for a straight lay; diagonal and herringbone patterns need about 15%.
  3. Divide by box coverage. Flooring is sold in boxes covering a fixed area (printed on the label, usually 18–25 sq ft). Divide your total by that number and round up to whole boxes.

Formula: boxes = ⌈(area × (1 + waste%)) ÷ coverage per box⌉

Choosing the right waste factor

Buying slightly more than you need is cheaper than a second delivery — and leftover boxes from the same production batch are the only guaranteed color match for future repairs.

What this calculator assumes

Frequently asked questions

How much extra flooring should I buy for waste?

Add 10% for a straight lay in a simple room, 15% for diagonal or herringbone patterns and rooms with many corners, and up to 20% for complex layouts. The extra covers cutting waste, defective planks, and future repairs.

How many square feet are in a box of flooring?

Most laminate and vinyl plank boxes cover 18–25 sq ft; hardwood boxes commonly cover 20–25 sq ft. The exact figure is printed on the box — enter it in the calculator for a precise count.

Do I measure under furniture too?

Yes — measure wall to wall. Flooring runs under anything movable. Only permanent built-ins like fixed cabinets or kitchen islands can be excluded.

Should flooring from different boxes be mixed?

Yes. Pull planks from several boxes as you install so slight tone and pattern differences blend across the floor instead of forming visible patches.

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