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Flooring Calculator

Use this free flooring calculator to find out how many boxes of flooring a room needs. Enter the room size, pick laminate, hardwood, vinyl plank, or tile, choose the plank or tile size, and set the layout pattern. The calculator gives you the square footage, the boxes to order, and the piece count, with waste included.

How it works

Flooring is sold by the box, and each box covers a fixed number of square feet, so the job starts with the room area. Multiply the room length by the room width to get the square footage, then add a waste allowance for the pieces cut to fit at the walls. A straight lay needs about 10 percent extra, because every row ends with a cut piece, and a diagonal lay needs about 15 percent, because every piece along the walls is cut at an angle and the offcuts are harder to reuse.

The box count is the area to cover divided by the coverage of one box, always rounded up. You cannot buy part of a box, and running short means a second trip and possibly a different dye lot. The calculator also works out the piece count: it divides the box coverage by the area of one plank or tile to find how many pieces are in a box, then multiplies by the number of boxes. A box of laminate covering 20 square feet with planks of 48 by 7.5 inches holds 8 planks, because each plank covers 2.5 square feet.

Plank and tile sizes change the piece count but not the box count, which depends only on area. Laminate and vinyl planks are commonly 48 inches long and 7 to 7.5 inches wide, hardwood planks are often 36 inches long and 5 inches wide, and tiles come in 12 by 12, 18 by 18, and 24 by 24 inch squares. Pick the size that matches the product you are buying, and check the coverage printed on the box, since it varies by brand and thickness. If your box covers a different area, type it in and the count updates.

Measuring is straightforward for a rectangle: the longest length and the widest width, measured wall to wall. For an L-shaped room, split it into two rectangles, work out each area, and add them together. Subtract nothing for doorways unless a whole closet is staying unfloored, but do add closets and alcoves that are getting the same floor. Measure in feet and round each measurement up to the next inch, since the waste allowance already covers small errors.

Remember the extras that are not flooring. Most floating floors need underlayment, which is sold by the roll and covers the same area as the floor, plus spacers for the expansion gap around the edges. Tile needs thinset, grout, and a backer board, and hardwood needs nails or glue. Keep a full spare box after the job for future repairs, because the exact color and finish may be discontinued later, and a repair with a mismatched box stands out across a whole room.

Worked example

A living room measures 15 feet long by 12 feet wide. The floor is laminate planks, 48 by 7.5 inches, sold in boxes covering 20 square feet, laid straight with a 10 percent waste allowance.

Step 1: Find the room area — 15 × 12 = 180 sq ft.
Step 2: Add waste — 180 × 1.10 = 198 sq ft to cover.
Step 3: Find the boxes — 198 ÷ 20 = 9.9, rounded up to 10 boxes.
Step 4: Find the pieces per box — one plank covers 48 × 7.5 = 360 sq in, which is 2.5 sq ft, so a 20 sq ft box holds 20 ÷ 2.5 = 8 planks.
Step 5: Find the total pieces — 10 boxes × 8 planks = 80 planks.

The room needs 10 boxes of laminate, which is 80 planks. Nine boxes would only cover 180 square feet, exactly the bare room area with nothing left for cuts, so the tenth box is the waste allowance.

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