How this calculator works
The selected shape determines net floor area. Add the waste allowance and multiply by the price converted to dollars per square metre. Ellipse axes are full widths, not radii. Pentagon and hexagon modes require equal sides and angles. Budget mode reverses the cost relationship. This area estimate does not pack pieces into a roll or guarantee the seam layout.
Formula
rectangle = length x width; circle = pi r²; ellipse = pi x axis A x axis B / 4; regular n-gon = n s² / [4 tan(pi/n)]; order area = net area x (1 + waste); cost = order area x price.
Worked example
A 4 m by 3 m room has 12 m2 of floor. With 10% waste, order 13.2 m2. At $20/m2 the carpet material allowance is $264.
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Frequently asked questions
Does waste include every offcut?
It is an allowance. Narrow corridors, pattern matching and roll width can require a larger quantity than an area-based estimate.
Can I use a price per square yard?
Yes. Select the price basis separately from the dimension units. One square yard is exactly 0.83612736 m2.
Are fitting and underlay included?
No. The price is for the carpet quantity only. Add underlay, fitting, grippers and delivery separately.