Flooring calculator
Carpet calculator
Carpet coverage and whole-roll quantity using the selected product's net coverage.
Calculator result and formula
Carpet rolls or cuts to order: 2 rolls
Formula: L × W × (1 + waste) ÷ stated coverage
Formula ID: FLOOR-CARPET-001 · Version 1.0.0.
Inputs
- Floor length: Finished carpet area length Default: 18.
- Floor width: Finished carpet area width Default: 14.
- Roll coverage: Net coverage of the selected carpet roll or cut Default: 180.
- Waste factor: Allowance for seams, pattern matching and cuts Default: 10.
How this calculator works
This calculator divides finished carpet area plus seam and cut allowance by the selected roll or cut's stated net coverage.
- Measure the finished room dimensions.
- Enter usable coverage for the selected carpet roll or quoted cut.
- Increase allowance when seams, directional pile or pattern matching require it.
Worked example: Example: an 18 ft × 14 ft room with 10% allowance and 180 ft² roll coverage rounds to 2 rolls or cuts.
Assumptions and limitations
- Coverage should use the selected manufacturer's product label or quoted net coverage.
- Waste is added before whole-unit purchase rounding.
- Complex layouts, seams or patterns can require a higher documented allowance.
Common questions
- Does it optimise carpet seam layout?
- No. Seam layout, roll width, pattern repeat and room geometry require a detailed installer takeoff.
- Can I use this for carpet pad?
- Use the separate underlayment calculator with product-specific roll coverage.
Reference notes
Related calculators
Enable JavaScript to use the interactive calculator and save a project estimate.