Oils on the hive are weighed in grams and so forth, but these oils usually come with a liquid measurement such as 5mls, 100mls, 1L, whatever.. How can you do a ml to gram conversion? i'm sure it's not one-to-one because of density i believe? Like water at 0c stp is meant to be 1ml = 1gram, right? but say something like lavender oil which is much heavier than water.. How would you work out how much 1ml of lavender oil would weigh or something?