Flooring Calculator (Boxes & Cost)
Enter your room's length and width in feet, add a waste percentage for cuts and mistakes, and tell the calculator how many square feet one box covers and what it costs. It returns your floor area, the area you should actually buy once waste is added, the number of boxes rounded up, and the total material cost — so you can price a project before you get to the store.
Room & product
Box coverage & price
Boxes to buy
10
198.00 sq ft ÷ 20.00 sq ft/box, rounded up
Total cost
$450.00
Floor area
180.00 sq ft
Area & cost detail
Floor area vs. area with waste
How it works
Floor area is simply length × width in feet. The calculator then multiplies that by one plus your waste percentage: at 10% waste, 180 sq ft becomes 198 sq ft of material to purchase. This buffer covers the pieces you cut to fit at walls and doorways, the offcuts you cannot reuse, and a few boards kept back for future repairs.
The purchase area is divided by the coverage printed on the box, and the result is always rounded up — you cannot buy a partial box, so ceiling arithmetic is the honest choice. For example, 198 sq ft at 20 sq ft per box is 9.9 boxes, which rounds to 10. Total cost is that box count multiplied by the price you enter per box.
Coverage per box is the number that varies most between products, so it is a field you set rather than a fixed assumption. Check the box or the product page for the exact square footage — thicker planks, wider formats, and specialty tiles all pack different amounts per box, and using the wrong figure is the most common way an estimate goes wrong.
Frequently asked questions
Why should I buy extra with a waste percentage?+
Every install produces offcuts: boards cut to fit against walls, around doorframes, and at the ends of rows rarely leave a usable remainder. A waste buffer of 5–10% is typical for a simple square or rectangular room laid in a straight pattern, while 15% or more is sensible for diagonal layouts, herringbone, busy patterns, or rooms with lots of corners and closets. Buying a little extra also leaves you matching boards from the same dye lot for future repairs, which is hard to source later.
Why do I have to enter the coverage per box myself?+
Because it genuinely varies by product and there is no reliable industry default. A box of laminate might cover around 20 sq ft, luxury vinyl plank often 24–30 sq ft, and hardwood or specialty tile something else entirely. The figure is printed on the carton and on the retailer's product page. Entering the real number for the exact product you plan to buy is what makes the box count and cost accurate — a generic assumption would quietly mislead you.
My room isn't a simple rectangle — what do I do?+
Break the space into rectangles. Measure each section — the main room, an alcove, a hallway, the area inside a closet — calculate the area of each, and add them together to get a total before applying waste. For L-shaped rooms this is usually two rectangles; for a bay window or bump-out, add that piece separately. When a room is very irregular or has angled walls, round each section up slightly and lean toward the higher end of the waste range.