How hitcap.io works
Every calculator on this site is open math: the formula, the sources we check it against, and breakpoint tables generated straight from the same code the tools run — so the numbers here can't drift from the calculators.
Formulas & sources
Combat rating converter
effect = rating / ratingPerUnitEach combat rating converts to its effect by a fixed level-70 divisor — 15.77699 for melee hit, 12.62 for spell hit, 3.94 per expertise skill, 2.3654 per defense skill, 39.4231 per 1% resilience, and so on. These are Blizzard's canonical level-70 conversions.
Sources: Blizzard "Combat Ratings: Level 70 Conversions" post (Blue Tracker); Wowhead TBC stats overview.
Arena points
points = basePoints(rating) × bracketMultiplierA logistic curve turns team rating into weekly base points; each bracket (2v2 0.76, 3v3 0.88, 5v5 1.00) scales it. The reverse tool inverts the curve by bisection, so it works for any monotonic profile. You only earn from your single best bracket — points do not stack.
Sources: Original 2007 Blizzard arena formula, anchors sanity-checked against community data (see manual-verification.md §3).
Melee & spell hit caps
cap% = baseMiss(Δlevel) [+19 for dual-wield white hits]Your miss chance depends on the target's level gap. +Hit subtracts from it; the cap is the hit% that drives miss to zero. Specials cap lower than dual-wield white swings (which carry a flat +19% penalty). Spell hit is a separate, steeper table that caps at 16% vs a +3 boss.
Sources: Wowhead / wowwiki TBC theorycraft; melee section confirmed in-game (manual-verification.md §4).
Expertise cap
expertise = floor(rating / 3.94); dodge/parry removed = expertise × 0.25%Each expertise skill point removes 0.25% dodge and parry from your target. Against a +3 boss the dodge cap is 26 expertise and the parry cap (front only) is 56.
Sources: Warcraft Tavern / Icy Veins TBC stat guides.
Defense cap
skill = 350 + floor(rating / 2.3654); critTaken% = max(0, baseCrit(Δlevel) − 0.04 × bonusSkill)Defense skill above the 350 base removes 0.04% crit-taken per point. Crit immunity vs a +3 boss is the famous 490 defense skill; vs an even-level player it's 475.
Sources: TBC tanking guides; web-corroborated, in-game pass open (manual-verification.md §5).
Resilience
critChanceReduction% = rating / 39.4231; critDamageReduction% = min(30, 2 × that)Resilience reduces your chance to be critically hit (uncapped) and the bonus damage a crit deals (at twice the rate, capped at 30 percentage points in original TBC).
Sources: TBC PvP guides; web-corroborated, in-game pass open (manual-verification.md §6).
Armor penetration cap
armorIgnored = rating × 5.92; remainingDR% = armor / (armor + 10557.5)TBC armor penetration ignores a flat amount of the target's armor (not a percentage — that's WotLK). The cap is the target's effective post-debuff armor. The damage-reduction curve uses Blizzard's level-70 armor constant.
Sources: WoWWiki / Wowpedia / theorycraft guides; highest-uncertainty tool, in-game pass required (manual-verification.md §8).
Haste rating & GCD cap
haste% = rating / 15.77; GCD = max(1.0, 1.5 / (1 + haste%/100))Haste rating converts at 15.77 per 1% (melee and spell). The global cooldown shrinks from 1.5s but never below 1.0s — reaching that floor (the GCD cap) takes 50% haste, about 789 rating.
Sources: Blizzard level-70 conversions; deterministic GCD math (manual-verification.md §9).
Breakpoint tables
These tables are generated at build time by running the live calculator functions — they always match the tools.
What 100 rating buys (level 70)
| Stat | 100 rating | Per 1 unit |
|---|---|---|
| Melee hit | 6.34% | 15.77699 rating |
| Spell hit | 7.92% | 12.62 rating |
| Melee / ranged crit | 4.53% | 22.0769 rating |
| Spell crit | 4.53% | 22.0769 rating |
| Melee haste | 6.34% | 15.77 rating |
| Spell haste | 6.34% | 15.77 rating |
| Expertise | 25 expertise | 3.94 rating |
| Dodge | 5.28% | 18.9231 rating |
| Parry | 4.23% | 23.65 rating |
| Block | 12.68% | 7.8846 rating |
| Defense | 42 skill | 2.3654 rating |
| Resilience | 2.54% | 39.4231 rating |
Arena points by rating — TBC Anniversary (Season 1)
| Team rating | 2v2 | 3v3 | 5v5 |
|---|---|---|---|
| 1500 | 845 | 978 | 1111 |
| 1800 | 1632 | 1890 | 2147 |
| 2000 | 1834 | 2124 | 2413 |
| 2200 | 1875 | 2171 | 2467 |
| 2400 | 1882 | 2179 | 2476 |
Melee hit rating → %
| Hit rating | Melee hit % |
|---|---|
| 50 | 3.17% |
| 100 | 6.34% |
| 142 | 9.00% |
| 200 | 12.68% |
| 300 | 19.02% |
Spell hit cap by target level
| Target Δlevel | Cap % | Rating |
|---|---|---|
| Even (PvP) | 4% | 51 |
| +1 | 5% | 64 |
| +2 | 6% | 76 |
| +3 | 16% | 202 |
Expertise caps (vs +3 boss)
| Cap | Expertise | Rating |
|---|---|---|
| Dodge (soft) | 26 | 103 |
| Parry (hard, front) | 56 | 221 |
Defense crit-immunity threshold
| Target | Defense skill | Rating |
|---|---|---|
| Even (PvP) | 475 | 296 |
| +1 | 480 | 308 |
| +2 | 485 | 320 |
| +3 | 490 | 332 |
Verification
Every shipped number is web-corroborated and flagged for an in-game pass; the
running log lives in manual-verification.md in the repository.
Where a value is still web-only (armor penetration constants, some boss-armor
figures), the tool's notes say so plainly rather than implying certainty.