in your case: 40 droplets = 1 ml. quick google search: 20 droplets is 1 ml (screenshot below). too may variables (atmospheric pressure, temperature, viscosity, % ethanol, % water, dropper opening size, etc etc) all influence droplet size. and even if you personally got 40 droplets from 1 ml today, it might be 30 next week bc of these changing variables. meaning: droplet size changes over time. if I were you I would only use your method after calibrating 3 x every time before I'd get a dose.
you're playing with potentially dangerous medicine here so [1] get a prescription, [2] dilute minoxidil topical as I described or [3] stick with putting it on your head.
View attachment 166873