Damage & EHP Calculator
Calculate Effective HP and exact damage with penetration/reduction.
1. Target Status & EHP
Filled in health, armour and magic resist for Garen at level 11.
EHP (Physical)
3775
Mitigation: 51.3%
EHP (Magic)
2976
Mitigation: 38.2%
2. Attacker Status & Penetration
Filled in attack damage for Miss Fortune at level 11. Changing items rewrites attack damage, ability power, bonus AD and penetration as base plus items, so add rune values after you have settled on the build.
From items and runes only
3. Skill & Multipliers
The starting values are only an example of the format. For anything the ability picker cannot fill, copy the numbers from the skill table on the champion's page.
Physical Damage
Magic Damage
Applies to physical damage only
Physical damage only
Disclaimer & Notes
This calculator processes the standard order of penetration and reduction. However, slight discrepancies from actual in-game values may occur due to complex overlapping mechanics.
The site's latest patch is 7.2d, but these figures come from 7.2. The 8 champions adjusted since then — Yone, Jinx, Leona, Rumble, Nasus, Ryze, Jayce, Nidalee — no longer match the live game.
Health, resistances and attack damage filled in by the champion picker come from the China-server official champion library (patch 7.2, as of 2026-08-25). Items and runes are not included.
Final Damage Result
Total Damage
95
5% of the target's 1838 remaining health — 20 casts to kill
How this is calculated
Mitigation from resistances is 100 / (100 + resistance). At 50 armor you take 67% of the raw damage.
Penetration applies as % first, then flat, and resistance never drops below 0. Reduction is applied before penetration.
The critical multiplier affects physical damage only. True damage ignores resistances and is only changed by damage amp and reduction.
EHP is effective health after mitigation: health ÷ (1 − mitigation).
Combo Builder
Total Damage
95
1838 HP left
20 to kill
Using the Damage Calculator
A tool for one question: does this combo actually kill? You fill in the attacker on one side and the target on the other, and the result is broken out into physical, magic and true damage.
Where the input numbers come from
Pick a champion and level to fill in health, attack damage and resistances. You can add up to six items, and their attack damage, ability power, resistances and penetration are added for you. Rune values still have to be entered by hand from the rune pages.
Only the ability base damage and ratios are typed in by hand — copy those from the skill tables on the champion's page. Item passives (the Infinity Edge critical multiplier, for instance) are written as prose, so they are not part of the calculation either.
Reading the result
The calculation covers a single cast. Raising the hit count simply multiplies it, so anything that happens mid-combo — a heal, a shield, omnivamp, tenacity — sits outside the model.
EHP is the damage a target really absorbs before dying. Add 50 armour to the target and watch how far EHP moves: that swing is what tells you whether penetration is worth an item slot. The formulas themselves sit under the result panel.
Enter values as they are written in the game and on this site. Where an in-game reading disagrees with a number here, trust the game.