Hardwood flooring calculator

Hardwood is sold by the carton with coverage on the label, and boards are often random length, so FlooringCalc works from area and treats the plank length as an average for the board count. This page starts with 5 in wide boards at $6 per sq ft: the 15 × 12 ft room needs 10 cartons of 20 sq ft and about 29 rows across the 12 ft width. Nail-down hardwood needs an expansion gap too, hidden under the baseboard.

Laminate, vinyl plank and hardwood

    Saved you some time? Leave a tip, entirely optional.

    Narrow strip flooring means more rows, more nails and more time, but the same square feet.

    How the flooring calculator works

    FlooringCalc multiplies the room's length by its width and adds any extra area for the square footage. It then adds a waste allowance for cuts that depends on the layout, divides by the coverage per box and rounds up, because flooring is sold only in whole boxes. The plank count divides the same area by the face area of one plank. Rows are laid along the longer wall, so the number of rows is the shorter dimension, minus a 3/8 in expansion gap at each wall, divided by the plank width. If the last row would be narrower than a third of a plank, the first and last rows are ripped to equal widths instead. Underlayment is the room area plus 5% for overlaps in 100 sq ft rolls, and trim follows the perimeter in 8 ft pieces.

    Waste by layout

    LayoutWaste added180 sq ft room needs
    Straight10%198 sq ft
    Diagonal15%207 sq ft
    Herringbone20%216 sq ft

    Rooms with many corners, closets or angled walls waste more than these figures, and so do long planks in short rooms. Trim counts do not subtract door openings. Follow the manufacturer's instructions for expansion gaps, acclimation and underlayment. Results are estimates for planning.

    Frequently asked questions

    How much waste for hardwood flooring?

    Plan on 10% for a straight lay and more for diagonal or herringbone, or if the boards are a lower grade with more defects to cut out.

    How many square feet in a box of hardwood?

    Often 18 to 25 sq ft for solid hardwood and 20 to 30 sq ft for engineered, but it varies widely by product.

    Should hardwood run parallel to the long wall?

    Usually, and across the floor joists for nail-down floors; it also makes the room look longer.

    Is FlooringCalc free?

    Yes, with no sign-up or ads.

    Are my numbers saved?

    Yes, in this browser only.

    More tools