1(kg/m3)= 0.001(g/cm3)= 0.0624(lb/ft3)
1(lb/ft3)= 16.02(kg/m3)
1(lb/in3)= 27679.9(kg/m3)
1(lb/gal3)= 119.826(kg/m3)
1(lb/gal3)= 99.776(kg/m3)
1(lb/bbl3)= 2.853(kg/m3)
1(B)=140/15.5℃－130
API=141.5/15.5℃－131.5