The milliliter is unit of volume and the milligram is the unit of mass, which cannot be directly converted, but the mass can be calculated by density and volume, and the calculation formula is: mass = density multiplied by volume.

For example, the density of water is 1000kg per cubic meter and the volume is 1 ml, so the calculation method of mass is:

1 ml =0.00 1 l =0.00000 1 m3. According to the mass calculation formula "mass = density times volume", it can be concluded that 1000kg ×0.00000 1 m3 = 0.000.