Damage Calculator - RPG/MMO Damage Formula Tool

Calculate damage output for RPGs and MMOs. Input stats like attack, defense, crit rate, and multipliers. Supports common damage formulas and custom equations.

Offensive Stats

Base Attack / ATK

Skill Multiplier (%) 100% = 1x damage, 200% = 2x damage

Crit Rate (%)

Crit Damage (%)

Defensive Stats (Target)

Defense / DEF

Damage Reduction (%)

Target HP

Damage Formula

Damage scales with attack vs combined stats

Damage Results

Base Damage

Crit Damage

Average

Detailed Breakdown

Combat Analysis

Hits to Kill

Non-Crit Hits	-
All Crits	-
Average (Expected)	-

Damage Efficiency

Defense Mitigation	-
Crit Value	-
Overkill	-

Stat Comparison

What if you increase a stat by 10%?

Stat	New Value	Avg Damage	Change

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Frequently Asked Questions

Common formula: (Attack - Defense) × Multiplier × Crit. Some games use Attack²/(Attack+Defense) or percentage-based reduction like Attack × (1 - Defense/1000).

Effective HP accounts for damage reduction from defense/armor. If you have 1000 HP and 50% damage reduction, your effective HP is 2000.

Critical hits multiply damage by a factor (usually 1.5x-2x). Expected damage with crits = Base × (1 + CritRate × (CritDamage - 1)).

Armor typically has diminishing returns using formulas like Damage × (100/(100+Armor)). Flat damage reduction (10% DR) reduces all damage by that percentage without diminishing returns.

It depends on current stats. If crit rate is low, stack attack. If attack is high but crit is low, adding crit gives better returns. Use the stat comparison to see which +10% helps more.

Most games use Reduction% = Armor / (Armor + Constant) × 100. The constant varies by game (often 100-500). League of Legends uses Armor/(Armor+100).

True damage ignores armor/defense. It's calculated as Attack × Multipliers only. Used in some games for balancing or anti-tank mechanics. Our calculator's 'ignore DEF' mode simulates this.

Penetration ignores a portion of enemy armor before damage calc. Reduction lowers enemy armor. Flat penetration applies before percentage. Order: Reduction → % Pen → Flat Pen → Defense.

In some formulas, yes. If the formula allows negative defense values, it amplifies damage. Most games cap defense at 0 minimum or use formulas that prevent this.

Balanced is often better due to diminishing returns. Pure attack hits a ceiling. Adding crit multiplies your attack's effectiveness. The optimal ratio varies by game but often favors 60-70% attack, 30-40% crit investment.