How it works
The calculator finds the floor area, adds your waste allowance, and divides by the area one plank covers. Boxes follow from the number of planks per box.
Area = Length × Width
Area of one plank = Plank length × Plank width
Area with waste = Area × (1 + Waste ÷ 100)
Planks = ⌈ Area with waste ÷ Area of one plank ⌉
Boxes = ⌈ Planks ÷ Planks per box ⌉
⌈ ⌉ means rounding up to the next whole number: you can’t buy part of a plank or a box.
All dimensions are converted to one internal unit before multiplying, so you can measure the room in feet and the planks in inches (or meters and millimeters).
Worked example
Inputs
- Measure by
- Room length × width
- Room length
- 14 ft
- Room width
- 11 ft
- Plank length
- 48 in
- Plank width
- 7 in
- Planks per box
- 10
- Waste allowance
- 10 %
Result
- Floor area
- 154 sq ft
- Area of one plank
- 2.33 sq ft
- Area incl. waste
- 169.4 sq ft
- Planks
- 73
- Boxes
- 8
Common mistakes
- Using a rounded size from the product name instead of the actual plank dimensions on the box. Small differences add up over a whole room.
- Entering the plank length in feet when the field is set to inches (or the reverse). Check the unit next to each field.
- Leaving the waste allowance at 0. Every row ends with a cut plank, and short offcuts can’t always start the next row.
- Forgetting closets, alcoves and the floor inside door openings where the planks continue.
Assumptions and limits
- The room is a rectangle, or you have entered its total floor area.
- The count is an area estimate. It divides the area by the face area of one plank and does not plan individual rows, cuts or offcut reuse.
- The plank drawing is schematic. Real stagger rules and minimum end-joint offsets come from the manufacturer’s instructions.
- Planks and boxes are rounded up to whole numbers. Without a box count, only the number of planks is shown.
- Underlayment, transitions and baseboard are not included.
Frequently asked questions
How much extra vinyl plank should I buy?
It depends on the room shape, the plank length and the layout. The manufacturer’s installation guide and your retailer are the best source for a figure. Rooms with many corners, doorways and angled walls need more than a simple rectangle, and many people keep a spare box for repairs.
My box lists square feet, not planks. What do I enter?
Most boxes list both. If yours only lists coverage, divide the coverage per box by the “area of one plank” shown in the results and round to the nearest whole number to get planks per box. You can also use the laminate calculator, which works from coverage per box.
Does the click joint change the plank size I should enter?
Enter the plank size the manufacturer lists for coverage. If the data sheet lists more than one size, use the one it gives for coverage, and compare the result with the coverage printed on the box.
Sources
- NIST Handbook 44, Appendix C – General Tables of Units of Measurement — National Institute of Standards and Technology. Exact unit definitions: 1 in = 2.54 cm, 1 yd³ = 27 ft³, 1 US gal = 231 in³, 1 lb = 0.45359237 kg.
Method reviewed November 2, 2026