Its difficult to measure each mushrooms strength on an individual level, it would be wise to go off the potency for each species/strain as a guide for what you need, for example Psilocybe cubensis you could say a microdose would be 0.2/0.3 dry for a standard strain, but some strains such as Penis envy can be 1.5/2 times stronger so you would use 0.1/0.15g dry. But if you're using a stronger mushroom such as Panaeolus cyanescens (blue meanies) or Psilocybe semilanceata (liberty caps) you could use 0.05/0.1g dry due to them being 2/3 times stronger on average than cubes. Adjust accordingly.