Quantity estimate only. This does not approve structural safety, load capacity, drainage, fire resistance or building-code compliance. Verify the design and local requirements with a qualified professional. Purchase quantities round up to whole packs.

Examples
Area & size
Dimension unit
Material (supplier values)
kg/m²
m/m²
screws/m²
Waste / allowance
%

Use a decimal point. Each rectangle line is length width, optionally followed by an integer quantity. All dimensions use the selected unit. Openings are deducted. Maximum 100 rectangles and 100 openings.

Assumptions & formula

Formula and assumptions

w = Waste allowance/100; N=ceil(S(1+w)/(LW)); kg=S(1+w)×rate; tape=S(1+w)×rate; screws=ceil(S(1+w)×rate)

The prefilled values are editable examples, not product specifications. Enter your supplier’s yield, density, coverage and packaging values, and add an allowance for overlaps, compaction and cuts where needed.

Purchase counts use the exact entered decimals and unit factors, without a rounding tolerance that could discard a real remainder. π and irrational square roots use enclosing bounds; ambiguous counts produce an error. Counts must be safe integers.

Results

Enter values and press Calculate to see the result here.