League of Legends Resistance & EHP Calculator

Effective Health Points (EHP) is a calculation that shows how much raw damage your champion can take before dying, accounting for resistances. It's a more accurate measure of tankiness than just looking at your health bar, as it factors in how armor and magic resist reduce incoming damage.

Armor penetration reduces your effective armor, making physical damage more effective against you. Flat penetration subtracts directly from your armor value, while percentage penetration reduces your armor by that percentage. Black Cleaver stacks can further reduce your armor by up to 30% when fully stacked.

Different champions deal different ratios of physical, magical, and true damage. Understanding the enemy team's damage composition helps you prioritize which resistances to build. For example, if facing a team that deals 70% physical damage, building armor will be more efficient than magic resist.

Flat penetration (like Lethality items) reduces the target's armor or magic resist by a fixed amount. Percentage penetration (like Lord Dominik's Regards or Void Staff) reduces resistances by a percentage of their total value. Percentage penetration is more effective against targets with high resistance values.

To maximize EHP: 1) Balance health and resistances rather than stacking just one, 2) Consider the enemy team's damage composition and build accordingly, 3) Be aware of enemy penetration items and adapt your build, 4) Remember that against true damage, only health increases your EHP as true damage ignores resistances.

The optimal balance depends on several factors. Generally, the more health you have, the more valuable resistances become, and vice versa. Against enemies with percentage health damage, resistances become more valuable. Against enemies with high penetration, health becomes more valuable. This calculator helps you find the most gold-efficient combination.