Thank you.
They are calculated based on the settings of the minimum and maximum level of enemies. For the default values (1-5), this is:
common biters health are (lvl1-10): 15,41,69,133,172,216,333,666,1000
melee damage: 7,13,19,25,32,41,52,66,90,115
spitters health: 10,27,45,99,166,233,300,450,850,1250
But not everything is so simple.
1. The stats have a small spread relative to the reference ones
2. Some factions have reduced health (e.g. electric), or increased (physical)
3. Special types of damage may differ significantly from the specified "normal" types. For example, "level 1 hell spitter" is still extremely dangerous
The most reliable way is to hover the cursor and look. There, sometimes, very interesting information )
