Damage Calculator

Formula reference · ARAM Mayhem · vs 100 armor / 50 MR baseline

Build Calculator

Attacker

Lv9

Target

Lv9

Item Build

Select an attacker and target to calculate damage

Formula Reference

Physical Damage Pipeline

↗ wiki.leagueoflegends.com/en-us/Damage

Pre-mitigation

Base AD × crit_multiplier

Armor mitigation

damage × 100 / (100 + effectiveArmor)

Effective armor

(targetArmor × (1 − %pen)) − lethalitymin 0

Magic Damage Pipeline

↗ wiki.leagueoflegends.com/en-us/Damage

Pre-mitigation

AP × ability_ratioratio varies per spell

MR mitigation

damage × 100 / (100 + effectiveMR)

Effective MR

(targetMR × (1 − %magic pen)) − flat magic penmin 0

Critical Strike

↗ wiki.leagueoflegends.com/en-us/Critical_strike

Auto-attack crit

2.0 + Σ bonus_crit_damagebase 200% since v26.01

Ability crit

1.45 + Σ bonus_crit_damageJeweled Gauntlet / Vulnerability

Bonus crit stacking

additive between items/augments

Average auto damage

AD × (1 + critChance × (critMod − 1))

Crit chance cap

100%

Damage Amplification

↗ wiki.leagueoflegends.com/en-us/Damage

Stacking rule

multiplicative between all sources

Formula

total = base × Π (1 + amp_i)

Example

20% + 20% = 1.20 × 1.20 = 1.44×not 1.40×

Giant Slayer — scales with target bonus HP (>1750)

Infernal Might — flat AP additive with items, not a multiplier

Armor Penetration Order

↗ wiki.leagueoflegends.com/en-us/Armor_penetration

1.Flat armor reduction— from abilities (can go below 0)
2.% armor reduction— e.g. Black Cleaver — stacks multiplicatively
3.% armor penetration— e.g. Lord Dominik's — multiplicative
4.Lethality (flat pen)— 1:1 since v14.1, applied last — min 0

Magic Penetration Order

↗ wiki.leagueoflegends.com/en-us/Magic_penetration

1.Flat MR reduction— from abilities (can go below 0)
2.% MR reduction— stacks multiplicatively between sources
3.% magic penetration— e.g. Cryptbloom — multiplicative
4.Flat magic penetration— e.g. Sorcerer's Shoes — applied last, min 0

Healing: Life steal → basic attacks only. Omnivamp → all damage (33% for AoE/periodic).

Damage Types

↗ wiki.leagueoflegends.com/en-us/Damage

physical — mitigated by armor

magic — mitigated by magic resistance

True — bypasses all resistances; still blocked by shields & invulnerability

Raw — bypasses resistances AND shields; only blocked by invulnerability

Special Interactions

↗ wiki.leagueoflegends.com/en-us/Damage

Jeweled Gauntlet / Vulnerability — abilities crit at 145% base (not 200%). Bonus crit damage additive on top.

True — unaffected by pen or reduction; damage amp DOES apply.

Giant Slayer — bonus damage vs high-HP targets; multiplicative with other amp.

Augment Interactions by Type

Parsed from augment descriptions · 0 augments have damage-relevant effects · sorted by win rate within tier

AD Items · Physical Damage Profile vs 100 Armor

Eff AD = AD × 100/(100+armor) · Crit Hit = Eff AD × (2.0+bonus_crit) · Avg × = weighted by crit chance · Armor pen order: %pen first, then lethality

Item	AD	Crit%	+Crit%	Leth	Pen%	Eff AD	Crit Hit	Avg ×
The Golden Spatula	90	25%	—	—	—	45.0	90.0	1.25×
Golden Spatula	90	15%	—	—	—	45.0	90.0	1.15×
Infinity Edge	75	25%	+30%	—	—	37.5	86.3	1.32×
Bloodthirster	70	—	—	—	—	35.0	70.0	1.00×
Ravenous Hydra	70	—	—	—	—	35.0	70.0	1.00×
Hexbolt Companion	70	—	—	—	—	35.0	70.0	1.00×
Hemomancer's Helm	70	—	—	—	—	35.0	70.0	1.00×
Twilight's Edge	70	—	—	—	—	35.0	70.0	1.00×
Voltaic Cyclosword	60	—	—	20	—	33.3	66.7	1.00×
Prowler's Claw	60	—	—	20	—	33.3	66.7	1.00×
Galeforce	65	25%	—	—	—	32.5	65.0	1.25×
Regicide	60	—	—	15	—	32.4	64.9	1.00×
Serylda's Grudge	50	—	—	—	40%	31.3	62.5	1.00×
Youmuu's Ghostblade	55	—	—	22	—	30.9	61.8	1.00×
Serpent's Fang	55	—	—	19	—	30.4	60.8	1.00×
Death's Dance	60	—	—	—	—	30.0	60.0	1.00×
Endless Hunger	60	—	—	—	—	30.0	60.0	1.00×
Eclipse	60	—	—	—	—	30.0	60.0	1.00×
Spectral Cutlass	60	—	—	—	—	30.0	60.0	1.00×
Duskblade of Draktharr	50	—	—	20	—	27.8	55.6	1.00×
Immortal Shieldbow	55	25%	—	—	—	27.5	55.0	1.25×
Hexoptics C44	55	25%	—	—	—	27.5	55.0	1.25×
Goredrinker	55	—	—	—	—	27.5	55.0	1.00×
Fulmination	55	—	—	—	—	27.5	55.0	1.00×
Divine Sunderer	55	—	—	—	—	27.5	55.0	1.00×
Guardian Angel	55	—	—	—	—	27.5	55.0	1.00×
Profane Hydra	50	—	—	18	—	27.5	54.9	1.00×
Hubris	50	—	—	18	—	27.5	54.9	1.00×
Opportunity	50	—	—	15	—	27.0	54.1	1.00×
The Collector	50	25%	—	10	—	26.3	52.6	1.25×
Essence Reaver	50	25%	—	—	—	25.0	50.0	1.25×
Stormrazor	50	25%	—	—	—	25.0	50.0	1.25×
Maw of Malmortius	50	—	—	—	—	25.0	50.0	1.00×
Kraken Slayer	50	—	—	—	—	25.0	50.0	1.00×
Axiom Arc	45	—	—	18	—	24.7	49.5	1.00×
Edge of Night	45	—	—	14	—	24.2	48.4	1.00×
Hamstringer	45	25%	—	—	—	22.5	45.0	1.25×
Mercurial Scimitar	45	—	—	—	—	22.5	45.0	1.00×
Yun Tal Wildarrows	45	—	—	—	—	22.5	45.0	1.00×
Chempunk Chainsword	45	—	—	—	—	22.5	45.0	1.00×
Hextech Gunblade	45	—	—	—	—	22.5	45.0	1.00×
Statikk Shiv	45	—	—	—	—	22.5	45.0	1.00×
Trinity Force	40	—	—	—	—	20.0	40.0	1.00×
Titanic Hydra	40	—	—	—	—	20.0	40.0	1.00×
Stridebreaker	40	—	—	—	—	20.0	40.0	1.00×
Spear of Shojin	40	—	—	—	—	20.0	40.0	1.00×
Sundered Sky	40	—	—	—	—	20.0	40.0	1.00×
Black Cleaver	40	—	—	—	—	20.0	40.0	1.00×
Experimental Hexplate	40	—	—	—	—	20.0	40.0	1.00×
Hullbreaker	40	—	—	—	—	20.0	40.0	1.00×
Manamune	40	—	—	—	—	20.0	40.0	1.00×
Overlord's Bloodmail	40	—	—	—	—	20.0	40.0	1.00×
B. F. Sword	40	—	—	—	—	20.0	40.0	1.00×
Lord Dominik's Regards	30	25%	—	—	40%	18.8	37.5	1.25×
Mortal Reminder	30	25%	—	—	30%	17.6	35.3	1.25×
Blade of The Ruined King	30	—	—	—	—	15.0	30.0	1.00×
Terminus	30	—	—	—	—	15.0	30.0	1.00×

57 Mayhem AD items · champion base stats and multi-item stacking not yet modelled

AP Items · Magic Damage Profile vs 50 MR

Magic Mult = 100/(100+effectiveMR) · Eff AP = AP × MagicMult · Actual damage = AP × ability_ratio × MagicMult (ratios vary per champion spell)

Item	AP	MPen%	Flat Pen	Eff MR	Magic Mult	Eff AP
Wooglet's Witchcap	300	—	—	50.0	66.7%	200.0
The Golden Spatula	125	—	—	50.0	66.7%	83.3
Golden Spatula	110	—	—	50.0	66.7%	73.3
Stormsurge	90	—	15	35.0	74.1%	66.7
Everfrost	100	—	—	50.0	66.7%	66.7
Twilight's Edge	100	—	—	50.0	66.7%	66.7
Detonation Orb	90	—	12	38.0	72.5%	65.2
Shadowflame	90	—	10	40.0	71.4%	64.3
Hextech Rocketbelt	95	—	—	50.0	66.7%	63.3
Actualizer	90	—	—	50.0	66.7%	60.0
Hextech Gunblade	90	—	—	50.0	66.7%	60.0
Morellonomicon	90	—	—	50.0	66.7%	60.0
Night Harvester	90	—	—	50.0	66.7%	60.0
Horizon Focus	90	—	—	50.0	66.7%	60.0
Luden's Echo	85	—	—	50.0	66.7%	56.7
Crown of the Shattered Queen	85	—	—	50.0	66.7%	56.7
Moonflair Spellblade	85	—	—	50.0	66.7%	56.7
Zhonya's Hourglass	80	—	—	50.0	66.7%	53.3
Banshee's Veil	80	—	—	50.0	66.7%	53.3
Lich Bane	80	—	—	50.0	66.7%	53.3
Sanguine Gift	80	—	—	50.0	66.7%	53.3
Demonic Embrace	80	—	—	50.0	66.7%	53.3
Reality Fracture	80	—	—	50.0	66.7%	53.3
Runecarver	80	—	—	50.0	66.7%	53.3
Cruelty	80	—	—	50.0	66.7%	53.3
Void Staff	65	40%	—	30.0	76.9%	50.0
Nashor's Tooth	70	—	—	50.0	66.7%	46.7
Archangel's Staff	70	—	—	50.0	66.7%	46.7
Innervating Locket	70	—	—	50.0	66.7%	46.7
Empyrean Promise	70	—	—	50.0	66.7%	46.7
Malignance	70	—	—	50.0	66.7%	46.7
Cryptbloom	60	30%	—	35.0	74.1%	44.4
Rabadon's Deathcap	65	—	—	50.0	66.7%	43.3
Cosmic Drive	65	—	—	50.0	66.7%	43.3
Shurelya's Battlesong	65	—	—	50.0	66.7%	43.3
Imperial Mandate	65	—	—	50.0	66.7%	43.3
Staff of Flowing Water	65	—	—	50.0	66.7%	43.3
Dusk and Dawn	60	—	—	50.0	66.7%	40.0
Riftmaker	60	—	—	50.0	66.7%	40.0
Blackfire Torch	60	—	—	50.0	66.7%	40.0
Rylai's Crystal Scepter	60	—	—	50.0	66.7%	40.0
Rod of Ages	60	—	—	50.0	66.7%	40.0
Ardent Censer	55	—	—	50.0	66.7%	36.7
Guardian's Orb	55	—	—	50.0	66.7%	36.7
Liandry's Anguish	50	—	—	50.0	66.7%	33.3
Dawncore	50	—	—	50.0	66.7%	33.3
Statikk Shiv	45	—	—	50.0	66.7%	30.0
Echoes of Helia	40	—	—	50.0	66.7%	26.7
Moonstone Renewer	35	—	—	50.0	66.7%	23.3
Sword of Blossoming Dawn	35	—	—	50.0	66.7%	23.3
Redemption	30	—	—	50.0	66.7%	20.0

51 Mayhem AP items · ability ratios, champion base stats, and multi-item stacking not yet modelled