feh damage calculator

Estimate combat damage in Fire Emblem Heroes using a practical, simplified formula.

Attacker Atk

Damage Type

Defender Def

Defender Res

Weapon Triangle

Effective Damage

Attacker In-Combat Atk Bonus

Defender In-Combat Def/Res Bonus

Flat True Damage

Special Bonus Damage

Damage Reduction (%)

Number of Hits

Formula used: (((Atk + buffs) with effective/triangle modifiers) - target stat + true/special damage) × (1 - damage reduction), minimum 0 per hit.

Enter values and click Calculate Damage to see the breakdown.

How this FEH damage calculator works

This FEH damage calculator is designed to give you a fast estimate of how much damage a unit can deal in combat. It captures the core ideas of the Fire Emblem Heroes damage formula: attack value, target defensive stat, weapon triangle advantage, effectiveness, true damage, and percent-based damage reduction.

While FEH has many unique weapon effects and skill exceptions, this tool is excellent for planning builds, checking matchups, and testing stat lines before spending resources.

Core FEH damage formula (simplified)

Step-by-step calculation

Start with the attacker’s Atk and add in-combat Atk bonuses.
Apply effective damage if active (x1.5 Atk).
Apply weapon triangle modifier (advantage x1.2, disadvantage x0.8).
Subtract target defensive stat (Def for physical, Res for magical), including bonuses.
Add flat true damage and special bonus damage.
Apply percentage damage reduction.
Multiply by total number of hits.

Damage per hit never goes below zero in this calculator, which mirrors FEH behavior where negative damage is treated as 0.

Using the calculator effectively

1) Pick the correct damage type

Physical attackers target Def. Magical attackers target Res. Choosing the wrong target stat can dramatically change your predicted result.

2) Model in-combat boosts, not just visible buffs

Many FEH effects trigger during combat only. Add those values in the bonus fields for better estimates.

3) Don’t forget reduction effects

Skills that reduce incoming damage by a percentage can heavily swing matchups. Use the damage reduction input to evaluate whether your build secures a KO through enemy mitigation.

Practical FEH matchup tips

Stack Atk wisely: raw Atk plus effectiveness often outperforms small true-damage boosts.
Respect the triangle: weapon advantage can be the difference between chip damage and a one-round KO.
Plan for multi-hit units: brave effects and follow-up attacks scale total damage fast.
Test both phases: a unit might win on player phase and lose on enemy phase due to different skill triggers.

Important note about advanced FEH mechanics

FEH includes many advanced interactions: adaptive damage, defensive specials, miracle-style effects, first-hit-only reduction, bonus doubler logic, and skill-specific exceptions. This page intentionally uses a clean, general-purpose model so you can iterate quickly. For deep tournament-level simulations, pair this with detailed in-game testing.

FAQ

Is this calculator good for build planning?

Yes. It is ideal for quick comparisons and determining whether extra Atk, true damage, or more hits matters most.

Does it support every FEH skill?

No. It focuses on the most common core mechanics and provides a reliable approximation rather than a full combat engine.

Can I use negative values?

You can enter negative numbers for some fields if you want to represent debuffs or penalties, but practical inputs are usually non-negative.