Here's a rough breakdown from Claude:

"[...] psilocybin converts to psilocin in the body at roughly a 1:1 ratio by active effect [...]

Psilocybe cubensis (most common): Contains about 0.5-1.0% psilocybin by dry weight. Since psilocybin converts to psilocin in the body at roughly a 1:1 ratio by active effect, 30mg of psilocin would be equivalent to roughly 3-6 grams of dried P. cubensis.

Psilocybe semilanceata (liberty caps): Much more potent at 1-2% psilocybin content, so you'd need only about 1.5-3 grams dried.

Psilocybe azurescens: Even more potent at 1.5-2.5% psilocybin, requiring roughly 1-2 grams dried.

Important caveats:

- Individual mushrooms within the same species can vary by 3-5x in potency Growing conditions, harvesting time, and drying/storage methods all affect potency

- The caps are typically more potent than stems

- Fresh vs. dried makes a huge difference (fresh mushrooms are ~90% water)"

Have to note that the paper is from 2016; for those really interested, it's good to read recent review papers.