BALANCE TOOL

Armor / Damage Reduction Calculator

Calculate damage reduction, an Armor formula, and Effective Health for game balance design.

Final Damage

Armor Comparison

What is the Armor / Damage Reduction Calculator?

This tool calculates final damage from an incoming damage amount and a reduction rate, and also calculates a reference Armor formula and Effective Health using Armor and K.

Damage Reduction and Armor

25% Damage Reduction turns 100 damage into 75. Armor is not the reduction rate itself — it's converted into a reduction rate using a formula that varies by game.

How to Use

Choose one of the three calculation modes.
Enter values into the fields shown.
Optionally enter HP.
Press "Calculate" to see the result and comparison table.
Copy the result if needed.

Formula and Example

Reducing 100 damage by 25% gives a final damage of 75, preventing 25. Reducing 200 damage by 40% gives 120. Going from 100 to 60 requires 40% reduction. With Armor 100, K 100, and 100 damage, the reduction is 50% and final damage is 50.

Using This in Game Development

Useful for balancing enemy attack and defense stats, and for comparing Armor values against their resulting reduction rates.

What is Effective Health?

EHP is your effective durability once reduction is factored in. With 1000 HP, 25% reduction gives about 1333.33, and 50% reduction gives 2000.

The Armor Formula and K

Armor / (Armor + K) is a reference model for design purposes. With K = 100, an Armor of 50 gives 33.33%, 100 gives 50%, and 200 gives 66.67%. The higher K is, the lower the reduction rate for the same Armor. This is not a universal formula used by Unity or every game.

Notes

Enter a reduction rate below 100%. At 100%, EHP becomes infinite. Special cases like invincibility are handled separately by each game.

FAQ

What reduction does Armor 100 give?

It's not fixed — it depends on the game's Armor formula. With this tool's reference formula and K = 100, it's 50%.

Are Armor and Damage Reduction the same?

No. Armor is one of the inputs used to derive a reduction rate.

Does 50% reduction double effective HP?

In this EHP model, 1000 HP becomes equivalent to 2000.

Why does the formula differ between games?

Games use their own formulas to balance durability and progression.