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