Carpet rolls by area Calculator: measuring notes and method
Check full-width cuts
The tool treats each entered roll length as a purchasable rectangular piece. Many suppliers instead sell linear metres from a fixed-width roll. Confirm that ordering convention before interpreting a whole-roll count.
Create a room cutting plan
A narrow leftover strip may not cover another room despite having enough area. Lay the required room pieces out across the actual roll width to check usable cuts.
Formula
Effective roll area = (roll width − side overlap) × roll length. Rolls = area with waste ÷ effective coverage, rounded up.
Worked examples in metric and imperial units
Illustrative values match Reset example and stay fixed when you edit the calculator. Both columns describe the same calculation; converted inputs are rounded.
Metric worked example
- Total surface area
- 24 m²
- Roll width
- 4 m
- Roll length
- 5 m
- Side overlap
- 0 mm
- Waste allowance
- 15 %
Rolls to buy: 2
Imperial worked example
- Total surface area
- 258.3339 ft²
- Roll width
- 13.1234 ft
- Roll length
- 16.4042 ft
- Side overlap
- 0 in
- Waste allowance
- 15 %
Rolls to buy: 2
Follow the calculation
Lengths in this working are in metres.
- Effective width = 4 − 0 = 4 m.
- Effective area per roll = 4 × 5 = 20 m².
- Divide 27.6 m² including allowance by effective roll area and round up.
Reviewed 19 October 2026. How calculations are checked · Report a correction