Convert pounds per cubic foot to kilograms per cubic metre.

one pound (lb) = 0.45359237 kilograms (kg)
one kilogram (kg) = 2.20462262184878 (lb)
one cubic foot (ft³) = 0.028316846592 cubic metres (m³)
one cubic metre (m³) = 35.3146667214886 cubic feet (ft³)

Conversion factor for converting lbs/ft³ to kg/m³ :
2.20462262184878 ÷ 35.3146667214886 = 0.0624279605761424
Multiply lbs/ft³ by 0.0624279605761424 to get kg/m³