Measure the perimeter at the installation line. Subtract doorway widths only where trim will actually be omitted. Opening deductions in this calculator are lengths, not areas. The allowance covers measuring and cutting uncertainty, while purchase rounding adds whole stock lengths. Mitred corners still need a detailed cut plan; this estimate does not optimize them.
Worked reference example
Illustrative inputs in metres and SI units; the price is an example entered by the user, not a market quotation. Numeric reference verified by the automated test suite.
- Length
- 4
- Width
- 3
- Area deductions (trim tool: length)
- 0
- Stock length
- 2.4
- Allowance
- 10
- Price per purchase unit
- 2
- Result
- 7
- Cost (example currency units)
- 14
Calculation method
N = ceil((2 × (L + w) − O) × (1 + r / 100) / S)Measure. Calculate. Build.
- Use actual dimensions and split complex rooms into rectangles.
- Allow for cuts, joints and package sizes. Compare stock formats.
- Combine your results in a shopping list you can save and print.
Sources & limits
Planning estimates; verify measurements and product data before purchasing.
Prices are supplied by you. Area estimates do not establish a feasible cutting arrangement. These tools do not assess structural loads or issue construction approvals.