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CalcBelt

Flooring calculator

Measure one room or the whole floor and get the square feet to buy, with the makers' cutting allowance for laminate, vinyl plank or hardwood, boxes and underlayment.

Units
Layout
Room
Shape

Add closets and hallways as their own rooms. Split L-shaped rooms into two rectangles.

Boxes and underlayment
%

AHF and LifeProof: about 10%. Diagonal: our 15%.

sq ft

Printed on the box or the product page, for example 19.5.

Laminate to buy

198 sq ft

180 sq ft of floor plus 10% for cuts

Boxes
–Enter the coverage printed on the box
Underlayment
2 rolls100 sq ft per roll
Square meters
18.4

Cost estimate

per sq ft

Installed: $1,800 for 180 sq ft (range $720 to $2,520)

Typical US price $4 to $14 per sq ft (HomeGuide, Fixr, October 2026). Laminate, materials and labor.

per box
How it's calculated
  1. Floor: 180 sq ft
  2. Add 10% for cuts: 180 sq ft × 1.1 = 198 sq ft
  3. Underlayment: 180 sq ft ÷ 100 sq ft per roll = 2 rolls (rounded up)

Estimates use manufacturer data sheets and industry guides (sources). Check local codes and your supplier's figures before you order.

How to use the flooring calculator

  1. Pick the flooring and the layout. Straight runs along the room; diagonal runs at 45° and needs more extra.
  2. Enter each room's length and width, or choose Known area to type its square footage. Click Add another room for closets, halls and the other half of an L-shaped room.
  3. Tick Subtract this area for anything that won't get flooring, such as a kitchen island.
  4. Enter the coverage printed on the box to get the number of boxes, and check whether you need underlayment.

How to calculate flooring

Flooring to buy = floor area × (1 + cutting allowance)
Boxes = flooring to buy ÷ coverage per box, rounded up

Example: a 12 × 15 ft living room in laminate. 12 × 15 = 180 sq ft. With AHF’s 10% cutting allowance that’s 180 × 1.10 = 198 sq ft. If the box holds 19.5 sq ft, 198 ÷ 19.5 = 10.2, so buy 11 boxes. Underlayment in 100 sq ft rolls: 180 ÷ 100 = 1.8, so 2 rolls.

Box sizes differ from one product to the next, so the calculator asks for the figure on yours. Bruce’s 2 1/4 in unfinished oak strip, for example, comes 19.5 sq ft to a box.

Cutting allowance by flooring

Flooring Straight Diagonal Source
Solid hardwood 5% 10% Bruce (AHF)
Engineered hardwood 5% 10% Bruce (AHF)
Laminate 10% 15%* AHF TimberTru
Vinyl plank 10% 15%* AHF rigid core, LifeProof

*No laminate or vinyl maker we found gives a diagonal figure. 15% is our default: their 10% plus the 5 points Bruce adds for diagonal hardwood. Change it if your flooring’s instructions say otherwise. Bruce also asks for 10 to 15% on glued-down solid hardwood.

Hardwood’s allowance covers more than cuts: Bruce calls it a cutting and grading allowance.

Several rooms

Measure each room on its own and add a row for each one. Flooring that runs through doorways into a hall still needs the hall measured. For an L-shaped room, use two rectangles that don’t overlap. Use the square footage calculator for other shapes, or the tile calculator for tile floors, which also counts grout and thinset.

Questions and answers

How much extra flooring should I buy?

It depends on the flooring. Bruce asks for 5% extra on solid and engineered hardwood, 10% on a diagonal. AHF suggests about 10% for its laminate and rigid core vinyl, and LifeProof says to order about 10% more vinyl plank. The calculator uses these, and 15% for diagonal laminate or vinyl, which no maker publishes.

How do I calculate how many boxes of flooring I need?

Add the extra to the floor area, then divide by the square feet in one box and round up. A 12 × 15 ft room is 180 sq ft; with 10% extra that's 198 sq ft, and with boxes of 19.5 sq ft you need 198 ÷ 19.5 = 10.2, so 11 boxes.

Do I need underlayment?

Floating floors like laminate and engineered click planks go over an underlayment unless the planks have a pad attached, as AHF's instructions say. Some rigid core vinyl planks, such as LifeProof, have a pad attached. Rolls such as QuietWalk Plus cover 100 sq ft.

How do I measure a room for flooring?

Measure the length and width at the widest points, wall to wall, and include closets you'll floor. Split L-shaped rooms into rectangles and add them. LifeProof's instructions have permanent cabinets, vanities and islands installed first and the floating floor laid around them, so subtract their footprint.

How much does new flooring cost?

HomeGuide's 2026 figures for flooring installed, materials and labor: laminate $4 to $14 per square foot, luxury vinyl plank $4 to $16, engineered wood $7 to $20 and solid hardwood $11 to $25. Fixr's ranges are $6 to $14 for laminate, $3 to $11 for vinyl plank and $14 to $32 for hardwood.

How many boxes of flooring do I need for 300 sq ft?

Add the cutting allowance, then divide by the box. With 10% extra, 300 sq ft becomes 330 sq ft; with boxes of 19.5 sq ft that is 16.9, so 17 boxes.

How much vinyl flooring do I need for a 12 × 12 room?

12 × 12 = 144 sq ft, plus about 10% for cuts (LifeProof's figure) makes 158.4 sq ft, so buy enough boxes to cover at least 159 sq ft.

Sources

Figures checked October 2026.