How many mg are in 30 ml?

Well, isn't that a happy little question! It all depends on what substance you're talking about, my friend. You see, milligrams (mg) measure the weight of a substance, while milliliters (ml) measure the volume of a liquid. So, to find out how many milligrams are in 30 milliliters, you'll need to know the density of the substance you're working with. Just remember, there are plenty of happy little formulas out there to help you figure it out!