Vinyl plank flooring calculator

How this calculator works

It multiplies length by width, adds any closets or extra area, and adds a waste allowance for end cuts, the last row and the odd damaged plank. Then it divides by the coverage printed on the box and rounds up to whole boxes.

Most rigid-core vinyl planks have a pad attached, so underlayment is off by default. Over concrete, the list can add a polyethylene vapor barrier; each doorway gets one transition strip.

Worked example

A 20′ × 11′ kitchen and dining area on a concrete slab is 220 sq ft. With 10% waste you need 242 sq ft, which at 24 sq ft per box is 10.08 boxes, so the list buys 11 boxes (264 sq ft). One 10′ × 25′ roll of 6-mil poly covers the slab with laps, and the two doorways take two transition strips.

Tips before you buy

• Check the installation guide before buying underlayment. Many planks with an attached pad must not go over a second pad, and doing so can void the warranty.
• Vinyl plank still needs an expansion gap at the walls, usually about ¼″. It moves with temperature, especially near sunny windows.
• The subfloor must be flat. Most makers allow only about 3/16″ of variation over 10 feet; fill dips before you start rather than after.
• When a result comes out just over a whole box, consider the next box anyway. One spare box covers a damaged plank years from now.

Questions

How much extra vinyl plank should I buy?

Plan on 10% extra for a straight lay in a typical room. Rooms with many corners, diagonal layouts and herringbone patterns need 15% or more. The allowance is under Coverage and waste and changes the box count instantly.

How many square feet are in a box of vinyl plank?

Boxes commonly hold around 20 to 30 square feet, depending on plank width, length and thickness. The coverage is printed on the box label and the product page. Enter that number for an exact box count.

Do I need a vapor barrier under vinyl plank on concrete?

Vinyl itself is waterproof, but moisture from a slab can still cause mold or adhesive problems underneath. Many makers call for 6-mil polyethylene over concrete unless the attached pad already includes a moisture barrier. Follow the instructions for your product.

Can vinyl plank go in a bathroom?

Rigid-core and many flexible vinyl planks are rated waterproof, which makes them a common choice for bathrooms, kitchens and laundry rooms. Leave the expansion gap around tubs and toilets and seal it with a flexible caulk where the instructions allow.