Question: how much volume is 1 drop of water?
Answer: The minim was defined as one 60th of a fluid dram or one 480th of a fluid ounce. This is equal to about 61.6 μL (U.S.) or 59.2 μL (Britain). Pharmacists have since moved to metric measurements, with a drop being rounded to exactly 0.05 mL (50 μL, that is, 20 drops per milliliter).