Flooring Calculator
Calculate the floor area, waste allowance and number of boxes or cartons of flooring you need.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
Estimate cartons from room area, the waste allowance you choose and the coverage printed on the carton. A 10% allowance is only a starting example; cuts, layout, room shape and product instructions change the amount needed. Cost excludes extras and installation.
Worked example
calculated with the default values below
Room length 14 ft · Room width 12 ft · Waste allowance 10 % · Coverage per box 24 sq ft · Price per box 45 $ Floor area 168.0 sq ft · Area including waste 184.8 sq ft · Boxes to buy 8 · Estimated cost 360.00 $
General background references
Disclaimer
These calculators provide planning estimates only. Building codes, wiring regulations and safety requirements differ by country and change over time, and nothing here replaces a licensed professional or a permit. For structural, electrical or gas work, follow local code and have the installation inspected.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
B = ceil(L × W × (1 + w ÷ 100) ÷ c)
- L
- floor length
- W
- floor width
- w
- waste percentage
- c
- coverage per box
- B
- boxes needed
Boxes = ceil(room area × (1 + chosen waste %) ÷ box coverage). Dimensions and coverage use ft²; cost = boxes × entered price. Waste is user-selected, not an automatic rule by product or layout.
Frequently asked questions
How does waste affect the number of flooring boxes?
The estimate multiplies room area by the waste percentage entered, divides by box coverage and rounds up. For 14 × 12 ft, 10% waste and 24 sq ft per box, it gives 8 boxes. Ten percent is an example, not a rule; follow product and installer guidance.