Does anyone know how to determine how much Health a pet will get per level? I've got two pets that are the same level but the breakdown says they're getting different amounts. It it based on their base health, maybe? They're both level 12 (at the time of posting this). Violet has 200 base and gets 152 from level while Cosmo has 132 base and gets 144 from level.

Yes, it has to do with the pets base health. It also has to do with the element that they are attuned to. If the element is supposed to have higher health, then your pet will have higher health. Also, when you level up while adventuring in the adventure window, you can see how much health your pet gets every level up in the battle log.

It's also affected by how you allocate Proficiency points. A pet with more points into Health will gain more Health on a level up.

@T1g3r, A pet's element has no affect on their stats. It's their proficiency that alters stats, and that will only affect a stat if you put the points into it. The element information just tells you recommended stats to put prof points in


And yes, base health affects the level bonus in an exponential manner compared to the four base stats which just boost equal to the level.
Take some lv75s;
lv75 wild-caught, base hp 145, level bonus is 1270
lv75 high stat, base hp 1220, level bonus is 2462
lv75 max stat, base hp 2000, level bonus is 3327
lv75 supermax, base hp 2000+995, level bonus is 5426

Thank you everyone, I think I get it now.
Violet and Cosmo both have one Prof Point in health and it's rising consistently. Cosmo seems to be getting 12 health per level while Violet is apparently getting 12.67. The calculator I made may be a few points off since I'm not sure how that's rounded but it seems to be working well enough.