Unit size to Hex size, conversion rate?

Been trying to make some dungeon maps while using hex grid in roll20 and keep some kind of layout that's actually playable with tokens (ie: corridors being 2 hex wide, etc). For now, it's a disaster and I haven't been able to find an elegant way to do that, as if the Hexes were not...normal or something. Anyone figured out some way to use Hexes for maps (and I don't mean outdoor maps, but dungeon-like maps) that you can actually play on without half your tokens being through walls and whatnot? Also, are the hexes respecting the proper 120° internal angles and same side length? Doesn't feel symmetrical to me for some reason. Cheerios.

Prior to the Rugged Reroll update, hexes were indeed skewed in one axis. I don't know if this is still true, although measuring now works correctly. This thread from nine months ago goes into the different aspects that hexes had at the time. Konrad's measurements fit what I remember running into at the time, but honestly I gave up using hexes instead of trying to work things around them.