Why do my weighing scales have ml and g?
Well as a chemist the densities of water and any watery liquid like milk will be very close to 1 gram per milliliter (g/ml) -- within a few percent. However corn oil would be off since it is about 0.90 g/ml. Lard seems to be about 0.87 g/ml. So be careful, but I'd guess that most ingredients in a recipe would work if within 10%.