Max Levels and Limits
In Path of Exile 2 the highest waystone tier is 16, the highest area level is 80, monsters reach level 82, the best modifier tiers need item level 82, skill gems level to 20 (hard cap 40) and characters to level 100. Patch 0.5.5, from the game files.
What is the highest waystone (map) tier?
Tier 16. Waystone tiers run from 1 (area level 65) to 16 (area level 80).
Each tier adds one area level: tier N opens an area of level 64 + N.
Source: BaseItemTypes (Waystone (Tier N)), MapTiers
What is the highest area level?
80: tier 16 waystones and 9 special areas such as Crux of Nothingness, Eastern Enigma Chamber, Kalguuran Tomb.
All areas at level 80: Crux of Nothingness, Eastern Enigma Chamber, Kalguuran Tomb, Loathsome Mire, Simulacrum of Delusion, The Copper Citadel, The Iron Citadel, The Stone Citadel, Tomb of the Fallen Knight.
Source: WorldAreas.AreaLevel
What is the highest monster level?
82 in a level 80 map: Irradiated adds 1 monster level and a corruption or cleansing modifier adds 1 more.
Monster level is the area level plus these map effects; the monster stat tables themselves go up to level 100 but nothing in the game reaches that.
Source: WorldAreas, endgame map content and corruption modifiers
What is the highest item level that matters?
82. Items drop at the level of the monster that drops them, and the best modifier tiers need item level 82 (for example of the Infinite, of Tzteosh, of Haast).
Of the 1,662 prefixes and suffixes that can roll on gear, none needs more than item level 82. See every tier on the base type pages.
Source: Mods.Level of item modifiers with a spawn weight
What is the highest skill gem level?
20 by levelling a gem; corruption can add 1 and gear adds more, up to a hard cap of 40 that the skill tables stop at.
Gems gain levels from experience up to 20; every skill's level table has 40 rows.
Source: ItemExperiencePerLevel, GrantedEffectsPerLevel
What is the max character level?
100, after 4,250,334,444 total experience.
Each level from 2 to 100 gives one passive point.
Source: ExperienceLevels
How many passive skill points can you get?
125: 99 from levels and 26 from quests, plus up to 25 weapon set points and 8 ascendancy points.
Plan them on the passive tree. 23 ascendancy classes in this patch.
Source: ExperienceLevels; quest points as Path of Building counts them