Calculation method
Multiply room length by width, add the planned cutting allowance, divide by labelled coverage per carton, and round up because cartons are purchased whole.
Worked example: input to purchase quantity
A 15 ft × 12 ft (4.57 m × 3.66 m) room is 180 ft² (16.72 m²). A 10% allowance raises the planned coverage to 198 ft² (18.39 m²). If the product label states 20 ft² (1.86 m²) per carton, 198 ÷ 20 = 9.9, so the purchase quantity is 10 cartons.
From room dimensions to sealed cartons
Plank flooring is quoted by area but bought in whole cartons. This calculator multiplies a rectangular room’s length and width, adds an explicit allowance for cuts and selection, divides by the exact carton coverage, and rounds upward. It suits laminate, engineered wood, luxury vinyl, and similar plank products when their box states reliable square-foot or square-metre coverage.
Measure the floor plane at the installation boundary, not wall-to-wall through cabinets or islands that will remain permanently excluded. Split L-shaped rooms, closets, bays, and connected halls into non-overlapping rectangles and total them. Decide whether flooring continues under appliances, removable cabinetry, or door thresholds according to the installation plan and product instructions. Small deductions can create unusable savings, so a layout is better than aggressive subtraction.
Use the exact SKU's carton coverage
Nominal plank dimensions do not guarantee a carton’s coverage. Piece count, actual dimensions, and packaging can change between collections. Read the label or current manufacturer specification for the exact color and SKU. Do not transfer coverage from a sample board, an older carton, or a similar-looking product. In metric mode enter square metres per carton; the unit switch converts existing physical values rather than silently reinterpreting them.
Cartons must generally come from a compatible product and color lot. Combining unrelated coverage figures produces a mathematically neat but unusable total. Inspect labels at pickup or delivery. For natural or visually varied material, blend boards as directed so the installed field does not show clusters. Keep documentation for warranty and batch identification.
Set waste from the layout
A straight installation in a square room often uses offcuts more efficiently than a diagonal pattern or a space with many doorways. Herringbone, chevron, borders, feature strips, angled walls, damaged subfloor areas, and strict appearance selection can require a different allowance or a manufacturer-specific method. End cuts are reusable only when they meet minimum-length, joint-spacing, tongue-and-groove, and appearance requirements.
Check the first and last row widths before ordering. A room whose width creates a narrow final row may require ripping both sides, changing usable coverage. Center lines, expansion gaps, transitions, stair noses, and pattern alignment also influence the layout. The calculator deliberately does not infer these details from room area.
Separate planks from the installation system
Underlayment, vapor control, moisture testing, leveling products, adhesive, fasteners, trims, reducers, thresholds, baseboard, and tools are separate. Product instructions determine subfloor tolerances, acclimation, environmental conditions, expansion space, and whether underlayment is attached or added. Ignoring those requirements can cause failure even when carton arithmetic is perfect.
Round up to the displayed carton count, then consider a repair reserve from the same lot. A reserve is distinct from installation waste: it remains unopened or protected for future replacement. Balance that value against storage conditions and return policy. Before purchase, remeasure each zone, verify carton coverage, confirm direction and pattern, and check stock quantity. The result is an auditable order, not a substitute for a row-by-row layout.
Door jambs and transitions deserve a separate check because the visible direction may continue into a hall while the expansion strategy requires a break. Record which thresholds receive profiles and which rooms remain a continuous floating field. The carton total cannot decide that detail, but the decision can change cut reuse.
If the package lists both net and gross coverage, use the net installable coverage specified for ordering. Packaging dimensions, pallet area, and marketing estimates are not substitutes. Photograph the carton label and lot number before recycling boxes so a later warranty or repair question can be traced to the actual material.
Product and method reference
The external reference is provided to help verify product-specific planning context; its values are not copied into the calculator. Always use the current label for the material being purchased. Pergo installation resources.
Calculation and editorial review: October 29, 2026. Arithmetic runs in your browser; project inputs are not submitted to TwoCut.