Dried chile equivalent?

[Pierre]

I just bought some dried chile (de arbol, I think). I make a pico de gallo which calls for 30 grams of fresh jalapeño. What's the equivalent amount of dried? The nearby grocery (which isn't where I went) has various dried chiles; what are the equivalents?

[lafsalot]

De arbols are really hot, and tend to get even hotter when dried. Might want to just start out with a little, then add more to taste. ~ Cathy