Flooring Calculator
Estimate how much flooring you need in square feet and boxes, including a waste allowance.
How to use
Enter room length and width, set waste, enter coverage per box from the carton, then calculate.
How the calculation works
Room length and width are converted to feet, multiplied for area, adjusted for waste, then divided by coverage per box and rounded up.
Formula
area_ft² = length_ft × width_ft; adjusted = area_ft² × (1 + waste%/100); boxes = ceil(adjusted ÷ coverage_per_box)
Example calculation
A 12 ft × 10 ft room is 120 ft². With 10% waste → 132 ft². At 20 ft² per box → 7 boxes.
Assumptions
Room shape
Single rectangle
Material: flooring · Key: geometry
For multiple rooms, calculate each area and add the results.
Source: Geometric model
Default waste (%)
10%
Material: flooring · Key: waste
Pattern matches, diagonals, and many cuts may need more.
Source: Planning default — not a product specification
Default box coverage (ft² / box)
20 ft² per box
Material: flooring · Key: box_coverage
Placeholder until the user enters carton coverage from their product.
Source: Planning default — confirm with your product label or supplier quote. Not a lab or manufacturer certification.
Practical notes
- Buy from the same lot/dye lot when possible.
- Keep an extra box for future repairs if the product may be discontinued.
- Stairs, closets, and closets openings may need separate measurements.
Limitations
- Does not layout planks or optimize cut lists.
- Box coverage must come from your packaging.
- Irregular rooms need multiple rectangles added together.
FAQ
- Where do I find coverage per box?
- On the flooring carton or product specifications. Use the installed coverage value, not the carton exterior size.
- How much waste should I add?
- Many straight layouts use about 5–10%. Diagonals, herringbone, and complex rooms often need more.
Related calculators
Results are planning estimates. See the Calculator Disclaimer.