The Build Calculator

Flooring Calculator

Calculate flooring for any room or whole floor: square footage with the right waste factor for your material and layout, boxes to buy, underlayment rolls and total cost — works for laminate, vinyl plank, hardwood and carpet.

Closets, hallways — add their sq ft

Printed on the box label

Flooring to buy (incl. waste)
sq ft
room area
boxes
underlayment rolls

Enter a price per sq ft to estimate cost.

You might also need:Tile Calculator·Wallpaper Calculator

Flooring math

buy quantity = (room area + extra areas) × waste factor
boxes = buy quantity ÷ coverage per box, rounded up

A 16 × 12 ft living room in vinyl plank: 192 sq ft × 1.07 = 206 sq ft to buy — 11 boxes at 20 sq ft per box. Always round boxes up and keep one unopened spare box for future repairs; retailers take unopened returns, but discontinued colors can't be re-bought.

Waste factor by situation

SituationWaste to add
Rectangular room, straight lay5–7%
Hardwood (defect culling)10%
Multiple rooms + hallways10%
Diagonal layout15%
Herringbone / chevron15–20%

Before you order

  • Acclimate the boxes: wood and laminate need 48–72 hours flat in the room before installation.
  • Check dye/run numbers on every box — like tile, flooring color varies between production runs.
  • Plank direction: run planks parallel to the longest wall or the main light source; diagonal looks great but moves you up a waste bracket.
  • Tiling instead? The tile calculator handles per-tile math; baseboard paint is in the paint calculator.

Frequently asked questions

How much extra flooring should I buy?+

Add 5–10% for straight-lay laminate or vinyl plank in a rectangular room, 10% for hardwood, and 15% for diagonal layouts, herringbone patterns or rooms with many jogs and closets. The offcut from one row-end starts the next row, so simple rooms waste less than people fear.

How many square feet are in a box of flooring?+

Laminate and vinyl plank boxes typically cover 18–24 square feet; engineered hardwood 20–30; solid hardwood bundles vary by width. The exact coverage is printed on every box label — enter it in the calculator for a precise box count.

How do I measure a room for flooring?+

Length × width in feet gives square footage. For L-shaped rooms, split into rectangles and add them. Include closets and doorway thresholds, and measure to the middle of doorways where the new floor will meet the old.

How much does new flooring cost?+

Materials per square foot: vinyl plank $2–$5, laminate $1.50–$4, engineered hardwood $4–$9, solid hardwood $5–$12, carpet $2–$6 installed-adjacent pricing. Underlayment adds $0.30–$0.75 per square foot where required.

Do I need underlayment?+

Most floating laminate and vinyl floors need underlayment unless it is pre-attached to the planks — check the box. It smooths minor subfloor flaws, dampens sound and adds a moisture barrier over concrete. One roll typically covers 100 sq ft.

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