Flooring Calculator

How it works

The calculator multiplies the room's length by its width to get the floor area, then adds a waste allowance for the pieces you cut at walls, doorways and around fixtures that cannot be used elsewhere.

The area including waste is divided by the coverage of one box and rounded up to whole boxes, because that is how plank and tile flooring is sold. The cost estimate is based on the boxes you buy, not the bare floor area, so it reflects what you will pay at the checkout.

If your flooring is sold by the square foot rather than by the box, set the box coverage to 1 and the box count becomes the square footage to order.

Formula

room area       = length × width
area with waste = room area × (1 + waste % ÷ 100)
boxes to buy    = area with waste ÷ box coverage, rounded up
estimated cost  = boxes to buy × box coverage × price per sq ft

Example

A 12 ft × 10 ft room is 120 sq ft. With 10% waste you need to order 132 sq ft. Boxes of 20 sq ft give 6.6 boxes, so buy 7.

At $2.50 per sq ft, 7 boxes is 140 sq ft of material and costs $350.00. With the price left at 0 the cost shows as $0.00.

Assumptions and limitations

• The room is a rectangle. For an L-shaped or irregular room, split it into rectangles, run the calculator for each and add up the boxes.
• The waste factor is a judgement. 10% suits a straight layout in a simple room; diagonal layouts, patterned tile, wide planks and rooms with many corners or closets need 15–20%.
• The cost covers the flooring only. Underlayment, trim, transitions, adhesive, tools and labor are extra.
• Box coverage varies by product and sometimes by batch. Read the carton rather than relying on a typical figure.

Frequently asked questions