% exposure vs % Increased damage

How do they compare? Is it a 1:1 scale?
I tried tinkering around in PoB but I can't seem to find how to check if exposure influences calcs or not.

exposure is simply one of debuffs affecting enemy's elemental resistance. And you probably know that enemy resistance and your damage increases are different levels of multiplication.

Is there a wiki page or a website where I can find the exact numbers and calcs?

https://pathofexile.fandom.com/wiki/Resistance_penetration

If you do 100 damage, and a mob has 50% resists, you do 50 damage.
If you apply 10% exposure, they have 40% resists, you do 60 damage.
So exposure added 60/50 or 20% more damage.

If you the mob had 0 resists, you do 100 damage.
If you apply 10% exposure, they have -10% resists, you do 110 damage.
This is 10% more damage.

So exposure and penetration both work to increase damage, but are particularly useful vs high resist mobs and bosses.

OP: With the exception of more multipliers and perhaps crit chance until you reach 100%, the more of something you get, the less effective each new increment is. There are far more ways to get a lot of %increased damage than there are of getting higher exposure.

Note that multiple sources of exposure do not stack. Only the strongest one will apply.

https://www.poewiki.net/wiki/Resistance_penetration

The new and better Wiki.