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Flooring Calculator

Boxes of laminate, vinyl plank or hardwood for a room, waste included.

Laminate, vinyl plank and engineered wood are sold by the box, and every box states the square footage it covers. The maths is simple — the mistakes happen in the waste allowance and in rooms that are not the tidy rectangles on the plan. This calculator turns your room measurements into a box count with the cutting waste built in.

Straight plank layouts in a square room waste about 10 percent. Add closets, fireplaces, angled walls or a diagonal layout and 15 percent is the honest figure. Boxes left over in good condition can usually be returned, so rounding up is cheaper than a second delivery and a floor that stops two planks short.

Calculate

Enter your measurements — the estimate updates as you type.

Estimates for planning and buying only. Product coverage varies by brand — check the label of the exact product you buy.

How to use this calculator

Measure the room at its longest and widest points — old rooms are rarely perfectly square.
Measure closets and connected areas separately and add them in the extra area field.
Read the coverage per box from the actual product you are buying; it ranges from about 14 to 30 sq ft.
Set waste honestly for your layout, then round up to whole boxes.

How flooring boxes are calculated

Boxes = (room area + extra area) x (1 + waste) / coverage per box, rounded up. The waste covers end cuts, damaged planks and the starter pieces of each row, whose offcuts start the next row when the layout allows.

Worked example: A 12 ft x 12 ft room is 144 sq ft. With 10 percent waste the requirement is 158.4 sq ft, and at 20 sq ft per box that is 7.92 boxes — so 8 boxes, giving 160 sq ft of flooring.

Common mistakes to avoid

Measuring wall to wall in an out-of-square room at only one point, then discovering the far end is three inches wider.
Forgetting doorways, closets and the strip under radiators, which together can add a full box.
Opening every box at once — unopened boxes are returnable, opened ones usually are not.

Frequently asked questions

How much flooring should I buy beyond my room area?

Ten percent extra for simple straight layouts, 15 percent for diagonal layouts, rooms with many obstacles or when the plank is very wide. Keep a few planks after the job for repairs.

Does underlay come with flooring?

Some vinyl and laminate planks have attached underlay; others need a separate roll. Check the product description, and if it is separate, buy underlay to the same area as the room plus a small overlap allowance.

Should flooring run toward or away from the light?

The common practice is to run planks parallel to the longest wall and toward the main light source, which hides the joints. In hallways, run planks along the length of the hall.

How long should flooring acclimatise before laying?

Most manufacturers ask for 48 hours in the room where it will be laid, boxes flat and unopened, so the material adjusts to the room temperature and humidity. Always follow the figure printed for your product.

Go deeper: read our guide — Flooring Buying Guide: Waste, Acclimation and Underlay