How do you calculate void ratio in concrete?

1) weight of cement in one cube divided by density of cement = volume of cement in a cube:

2) Similarly volume of fine & Coarse aggregate can be calculated

3) Adding all one will get volume of solids in a Cube-Vs:

4) Subtracting Vs from volume of cube Vc one would get volume of voids Vv

5) taking ratio of Vv to Vs one would get void ratio