EHP (Effective HP)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The EHP (Effective Health Points) calculator is used to determine a character's effective health in RPG games, accounting for damage reduction (DR). EHP represents the actual health after applying damage mitigation. The formula is EHP = HP / (1 - DR), where HP is raw health and DR is damage reduction expressed as a decimal (e.g., 0.3 for 30%).
This tool helps compare character builds, evaluate gear with resistances, or balance combat strategies. For example, a character with 1000 HP and 50% DR will have EHP = 1000 / (1 - 0.5) = 2000 effective health points.
Ensure DR is input as a decimal between 0 and 1 (not 0% to 100%) and does not exceed 100%, as this would cause division by zero. Incorrect values may produce illogical or unusable results.
Frequently asked questions
What is EHP in RPG games?
EHP (Effective Health Points) is the actual health a character can sustain after accounting for damage reduction. It shows how much 'effective' health exists before the character dies, considering their defenses.
How to use the EHP formula EHP = HP/(1−DR)?
Plug in HP (raw health) and DR (damage reduction as a decimal). Example: HP=1000 and DR=0.3 → EHP = 1000/(1-0.3) = 1428.
Why can't DR be 100%?
100% DR (1.0 in the formula) causes division by zero, which is mathematically undefined. In games, values above 90%-95% are often clamped for balance.
Can EHP be lower than HP?
No. EHP is always equal to or greater than HP because damage reduction increases effective health. If DR=0, EHP=HP.