is ml same as mg?
If you have pure water then a ml is equal to a mg. Water is the only substance where this is true, because water was used as a common substance when devising the metric system, based on the earth. . Absoultely not! ml is milliliter, a measure of volume and mg is milligram a measure of weight. No. ml is milliliters 1ml=0.001l (1/1000 liters). This measures volume of a liquid. mg is milligrams 1mg=0.001g (1/1000 gram).