This article has not been updated for 3.0.
3.0 has introduced diminishing returns on a number of stats, and as such the formulas in this article are not always applicable. All non-scaling stats should remain the same, but any scaling stats have either or both 1) a different rating conversion 2) a non-linear scaling. This article will be updated with this information as the author has time to do so. Until such time, please refrain from adding comments pointing out inaccuracies unless you have relevant data to contribute. Thanks.
This article discusses the conversion of stats in to various attributes. There are two categories for this: non-scaling stats (such as Attack Power) and scaling stats (such as Armor Class or Critical Strike Rating). Non-scaling stats will provide the same benefit regardless of level. Scaling stats provide different benefits depending on your character level.
Agility and Intellect are both a scaling and non-scaling stat. The amount of dodge and crit Agility provides changes with level but its Attack Power and Armor Class contribution do not. Likewise the amount of spell crit chance that Intelligence gives changes with level but its mana pool contributions remain static.
Your character starts with a small amount of base stats that are ignored for these calculation purposes. This varies from class to class. All values listed on this page are what will be contributed from items with stats on them.
To determine the exact rating needed to give a 1%, multiply its level 60 rating equivalence by . For example, each 14 Critical Strike Rating was worth exactly 1% crit at level 60. The exact value needed for 1% Critical Strike at level 70 is:
These rating amounts will be listed when the present amount was derived from a level 60 rating.
Each point of Armor (AC) on an item raises your armor class value by that amount. Note that while the amount added to your AC is linear, the amount of damage mitigation that is added per point of AC is not. Damage reduction from AC is hard capped at 75%.
To calculate the damage reduction from your armor class, use the following formulas:
The level 70 version can be simplified as:
Defending against a level 73 NPC, the constant changes because of the NPC's level and the formula is:
Strength increases melee attack power.
2 points of AP per Strength: Warriors, Shamans, Druids (Bear Form, Cat form), Paladins
1 point of AP per Strength: Rogues, Hunters, Priest, Warlock, Mage
Additionally, every 25 points of Strength will increase your Shield Block Value by 1 for classes that use shields.
Agility increases attack power for some classes and ranged attack power for all classes that can use guns, bows, or crossbows.
1 point of AP per Agility: Rogue, Hunter, Druid (Cat form)
1 point of Ranged Attack Power per Agility: Hunter
2 points of Ranged Attack Power per Agility: Warrior, Rogue
Agility also increases Armor Class by 2 per point for all classes.
As of 2.4 all mana-using classes share the same mana regeneration formula that is a function of both spirit and intellect. Prior to 2.4 there were different formulas for different classes based soley on spirit.
Spell damage and healing increases your spell damage by 1 per point and your healing by 1 per point. The value of your damage or healing applied to a given spell cast varies. See the Spell Coefficients page for more information.
School-specific spell damage increases your spell damage with spells from that school by 1 per point. The value of your damage applied to a given spell cast varies. See the Spell Coefficients page for more information.
Spell penetration reduces your target's resistance to a all spell schools. This stat is not useful in PVE when Warlock curses are used; very few NPCs have resistances higher than what is negated by Curse of Shadows or Curse of Elements though a few exceptions do exist.
Restores the amount of mana specified over five seconds. All MP/5 values stack with each other; a past bug that has been corrected had prevented items with the same amount of MP/5 from stacking together (3 items that should have provided 5 MP/5 each for a total of 15 MP/5 only provided 5 MP/5).
All scaling stat conversions have their level 70 values posted. At lower levels, these values will produce greater-than-expected results, but they are not relevant to the rest of the content of the wiki.
Be wary that the UI will round some decimals up. While it may appear that you have "enough" of a stat, you may really be slightly short of that mark.
All "cap" values listed here disregard talents or any other stats that may synergize with it (i.e. Resilience and Defense Rating both decrease the chance to be critically hit). The amounts listed are "pure" for that stat.
Agility contributes chance to dodge for all classes.
Paladin, Shaman: 25 agility per 1% dodge.
Rogue: 20 agility per 1% dodge.
Druid: 14.71 agility per 1% dodge.
Warrior 30 agility per 1% dodge.
Agility contributes chance to critically hit with physical attacks for all classes.
Hunter, Rogue: 40 Agility per 1% crit.
Druid, Paladin, Shaman: 25 agility per 1% crit.
Warrior: 33 agility per 1% crit.
3.9423 rating grants 1 skill point.
Level 60: 2.5 rating per Expertise
Expertise removes .25% dodge and .25% parry from your opponent's defenses.
Note: Expertise only rounds to whole numbers (e.g. 1, 2, 3, 4, etc.) unlike Hit and Critical Strike which round to two decimal places. This means any extra rating above a multiple of 3.9423 does not have any effect at all.
2.4 rating grants 1 defense skill.
336 defense rating is required to reach 490 defense and crit immunity for Warriors and Paladins. Feral druids require 156 defense rating with Survival of the Fittest to reach 415 defense and crit immunity.
Level 60: 1.5 rating per Defense skill
15.76 rating grants 1% hit chance.
142 hit rating is needed to reach the 9% hit cap against boss mobs with one-handed weapons used in conjunction with a shield, two-handed weapons, feral attacks, ranged attack, or taunt.
443 hit rating is needed to reach the 28% hit cap against boss mobs when dual wielding.
Level 60: 10 Rating per 1%
15.76 rating grants 1% haste as of 2.2. Haste rating does not lower the global cooldown. There is no cap on haste, but anything that reduces attack speed below 0.5 seconds for Hunters is not useful due to the hidden cast time on autoshot.
Level 60: 10 Rating per 1%
15.76 rating grants 1% spell haste chance. Spell haste rating will lower the global cooldown up to .5, resulting in a 1.0 cooldown (requires approximately 785 spell haste rating). There is no cap on spell haste, but stacking enough haste to lower the cast time of a spell to be faster than the global cooldown is questionably useful at best and DPS will not improve by further stacking spell haste once this point is reached.
Level 60: 10 Rating per 1%
39.4 rating grants 1% less chance of a successful hit against you being a critical strike (spell or physical), 1% less damage from damage over time spells, and 2% less damage taken from critical strikes. Note that this reduction in critical strike damage is applied before any other modifiers, so talents that improve critical strike damage are heavily impacted in a negative fashion by resilience. Reduction in the amount of damage done by critical strikes caps at 25% less damage from critical strikes (493 rating), but there is no cap on the reduction of critical strike chance.
Level 60: Resilience 25 rating grants 1% resilience
Note: BASE_REGEN for a level 80 is 0.005575 and I have confirmed this with my shaman.
Note: This Formula appear in both the Stat Conversion and Five Second Rule Think Tank Articles
The information on Resilience needs to be updated to reflect that as of patch 2.4 it also reduces the amount of mana drained by the same amount as the Critical Damage Reduction. Also, as of Patch 3.0.3 the amount of Critical Damage Reduction and Mana Drain Reduction is 2.2 times the base percentage, and the Critical Damage Reduction now caps at 33%. As of Patch 3.2 it no longer reduces Damage from Damage over Time spells, but instead reduces all damage from players by the same amount. *EDIT* Also, as of Patch 3.2 the amount of Resilience needed for 1% has been increased by 15%.