How is hit chance worked out in RS3?

Hit chance = affinity × your accuracy ÷ the target's armour rating, plus any flat bonuses, capped at 100%. Your accuracy is a bonus from your level plus a bigger one from your weapon's tier; the armour rating is the target's armour plus a bonus from its Defence level.

What does affinity mean?

How easy a monster is to hit with each style: one number per style, from the wiki. Using a monster's weakness raises it, and affinity debuffs such as Statius's warhammer special or Bandos's Book of War add up to 10 more.

Is RS3 accuracy capped?

Yes, at 100%. Past that, extra accuracy does nothing, which is why the calculator tells you the lowest weapon tier that reaches 100% against your target.

What happens at low hit chance?

Abilities deal their average damage times your hit chance, so 80% hit chance costs about a fifth of your damage. Under 1%, every attack misses.

Where do the monster numbers come from?

From the RuneScape Wiki's monster infoboxes (Defence level, armour and affinities), read 2026-11-13. Monsters the wiki gives no armour for are left out.

RS3 accuracy calculator

Your hit chance against 3,553 bosses and monsters, from your level, weapon tier, potion, prayer and boosts, with the working shown.

How RS3 hit chance works

Every attack rolls against the target's armour rating. Your hit chance is the target's affinity for your style, times your accuracy, divided by its armour rating, plus any flat bonuses such as a Reaper necklace, capped at 100%.

Accuracy comes from two places: your level (boosted by potions and prayers) and your weapon's tier, which counts two and a half times as much. That is why a tier 95 weapon matters more than a few levels. Armour rating is the target's armour plus a bonus from its Defence level, both on the wiki's monster pages.

Formula: the RuneScape Wiki's hit chance page. Monster data: the RuneScape Wiki's monster infoboxes, read 2026-11-13. Accuracy perks, auras and set effects beyond the boosts listed are not modelled.

RS3 boss armour and affinities

Armour rating is the boss's armour plus f(its Defence level). Necromancy uses the middle of the three style affinities. "Accuracy for 100%" is what you need with its best style: armour rating × 100 ÷ affinity.

Boss	Defence	Armour	Rating	Melee	Ranged	Magic	Necro	Accuracy for 100%
King Black Dragon	60	1,132	1,584	60	50	70	60	2,263
Chaos Elemental	69	1,447	2,025	50	70	60	60	2,250
Kalphite QueenSecond form / First form	60	1,132	1,584	70	60	50	60	2,263
General GraardorHard mode	75	1,694	2,371	60	70	50	60	3,388
General GraardorNormal	60	1,132	1,584	50	10	50	50	3,168
General GraardorThe Mighty Fall	72	1,566	2,192	55	45	65	55	3,373
General GraardorThe World Wakes	72	1,566	2,192	40	30	50	40	4,384
Kree'arraHard mode	75	1,694	2,371	50	60	70	60	3,388
Kree'arraNormal	60	1,132	1,584	10	70	70	70	2,263
Kree'arraThe World Wakes	70	1,486	2,080	50	40	30	40	4,160
Commander ZilyanaHard mode	75	1,694	2,371	45	40	50	45	4,742
Commander ZilyanaNormal mode	60	1,132	1,584	40	40	40	40	3,960
K'ril TsutsarothHard mode	75	1,694	2,371	70	80	60	70	2,964
K'ril TsutsarothNormal	60	1,132	1,584	45	40	50	45	2,112
K'ril TsutsarothThe World Wakes	70	1,486	2,080	30	20	40	30	5,200
Queen Black DragonCarapace	80	1,924	2,693	40	40	70	40	3,848
Queen Black DragonCrystal	80	1,924	2,693	70	70	40	70	3,848
Queen Black DragonNormal	80	1,924	2,693	50	50	50	50	5,386
Hermod, the Spirit of WarNormal / Quest	70	1,486	2,080	55	55	65	55	2,312
Corporeal Beast	75	1,694	2,371	40	40	40	40	5,928
NexDeflecting melee / Standard / Deflecting ranged / Deflecting magic	80	1,924	2,693	40	40	40	40	6,733
VindictaHard mode	85	1,924	2,795	60	60	60	60	4,659
VindictaNormal mode	75	1,694	2,371	60	60	60	60	3,952
HelwyrHard mode	75	1,694	2,371	60	60	60	60	3,952
HelwyrNormal mode	70	1,486	2,080	60	60	60	60	3,467
GregorovicNormal mode	75	1,694	2,371	55	55	55	55	4,311
GregorovicSliske's Endgame / Hard mode	80	1,924	2,693	55	55	55	55	4,897
Astellarn	85	2,178	3,049	55	55	55	55	5,544
Crassian LeviathanNormal mode (south) / Normal mode (north) / Story mode (north) / Story mode (south)	85	2,178	3,049	55	55	55	55	5,544
Arch-GlacorHard mode / Normal mode	75	1,694	2,371	55	55	55	55	4,311
TzTok-Jad	70	1,486	2,080	55	55	55	55	3,782
Kalphite KingMagic	85	2,178	3,049	30	50	40	40	5,082
Kalphite KingMelee	85	2,178	3,049	40	30	50	40	5,082
Kalphite KingRanged	85	2,178	3,049	50	40	30	40	5,082
AraxxorMagic	85	1,924	2,795	40	60	45	45	4,659
AraxxorMelee	85	1,924	2,795	45	40	60	45	4,659
AraxxorRanged	85	1,924	2,795	60	45	40	45	4,659
Araxxi	80	1,924	2,693	60	60	60	60	4,489
The MagisterBoss	90	2,458	3,441	55	55	55	55	6,257
Seiryu the Azure SerpentStory mode / Normal mode	80	1,924	2,693	55	55	55	55	4,897
Masuta the AscendedPhase 1 (normal mode)	75	1,694	2,371	55	55	55	55	4,311
Masuta the AscendedPhase 2 (normal mode)	75	1,694	2,371	40	40	40	40	5,928
Verak Lith	70	1,694	2,288	55	55	55	55	4,160
Taraket the NecromancerNormal mode	70	1,694	2,288	55	55	55	55	4,160
Kerapac, the boundHard mode / Normal mode	80	1,924	2,693	55	55	55	55	4,897
Har-AkenHead	80	1,924	2,693	45	45	45	45	5,985
Har-AkenMagic Tentacle	76	1,738	2,433	50	70	60	60	2,704
Har-AkenRanged Tentacle	76	1,738	2,433	70	60	50	60	2,704
Vermyx, Brood MotherHard mode	85	2,178	3,049	70	60	60	60	4,356
Vermyx, Brood MotherNormal mode	85	2,178	3,049	65	55	55	55	4,691
Kezalam, the WandererHard mode	85	2,178	3,049	60	60	70	60	4,356
Kezalam, the WandererNormal mode	85	2,178	3,049	55	55	65	55	4,691
Vorago	90	2,178	3,161	40	40	40	40	7,903
Telos, the WardenStandard / Phase 5	80	1,924	2,693	40	40	40	40	6,733
Beastmaster Durzag	90	2,458	3,441	55	55	55	55	6,257
YakamaruNormal / North-eastern pool (Ranged) / Sick / North-eastern pool (Magic) / North-eastern pool (Melee)	99	3,031	4,243	55	55	55	55	7,715
The AmbassadorStory mode / Normal mode	75	1,694	2,371	55	55	55	55	4,311
Raksha, the Shadow ColossusSubdued / During fight / During fight (duo) / Shackled	85	2,178	3,049	55	65	55	55	4,691
TzKal-ZukHard Mode / Normal Mode	80	1,924	2,693	55	55	65	55	4,144
Zamorak, Lord of ChaosStory mode / Hard mode / Normal mode	80	1,924	2,693	55	55	55	55	4,897
Rasial, the First NecromancerNormal / Alpha vs Omega	95	2,458	3,563	55	55	55	55	6,479
Nakatra, Devourer EternalHard mode	110	3,862	5,406	60	60	60	60	9,010
Nakatra, Devourer EternalNormal mode	95	2,765	3,870	55	65	55	55	5,954
Amascut, the DevourerEclipse of the Heart	90	2,458	3,441	55	55	55	55	6,257
Amascut, the DevourerEmpowered / Regular	95	2,765	3,870	55	55	55	55	7,037

Questions

Gear and rotations for each fight are in the boss guides; more tools on the calculators page.

Start from your own levels.

Type your name and RuneSquire reads your combat levels from the Hiscores, then ranks every boss by how ready you are.

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