How to convert from kN/m3 to kg/m3?
Correctly measure in tf / m3 (ton-force per cubic meter). 1 tf / m3 = 1 t/ m3 .
1 kN/m3 = 0.1019716 tf/m3 = 0.1019716 t/m3 (with the acceleration of free fall g = 9.80665 m/s2)
if rounded, then 1 kN/m3 ≈0.1 tf/m3 = 0.1 t/m3 (with rounded gravitational acceleration g ≈ 10 m/s2).
Thus, to convert from kN / m3 to tf / m3, divide kN / m3 by 9.80665 (or divide by 10 when rounding).