Path of Building question

When I'm theroycrafting a build in Path of Building, occasionally I end up getting 'inf' effective hit pool. What does this mean? Is my build just straight-up immortal?

It depends but generally speaking no. For one PoB massively inflates how effective recovery mechanics are (especially life or es on block) which will make PoB think you are effectively immortal but the reality is your tankiness is no where near that level. The max hit for each damage type are a much better barometer.

You also could have normal enemy selected which you would be effectively immortal against but no one judges a build based on how well it handles white mob auto attacks.

Oh yeah. That makes much more sense. I have 53mil ehp against normal mobs... but only 138K against a pinnicale boss. Thanks.

And I had endurance charges accidentally ticked on. Now against normal mobs I have 658K ehp.