500 mg equals how many mL?

To convert milligrams (mg) to milliliters (mL), you need to know the density of the substance in question. Since density varies for different substances, a direct conversion from mg to mL is not possible without this information. If you are working with water, which has a density of 1 g/mL, then 500 mg would equal 0.5 mL. However, for other substances, the conversion would be different.