With this online calculator you can convert ml to drops (milliliters to drops).
Formula:
N = V / V1
N - number of drops
V - volume
V1 - volume of one drop
Pharmaceutical measure of a drop:
For aqueous solutions 1 drop = 0.05 ml (20 drops is 1 ml).
For alcohol solutions 1 drop = 0.025 ml (20 drops is 0.5 ml).
Drop is the amount of liquid that takes a round shape due to the cohesion of its particles.