How To Calculate Damage Increases In Diablo 4? - Damage & Defense Mechanics Explained

Today’s topic will be Diablo 4 mechanics. We will be talking about damage buckets, damage, how to calculate damage increases and defenses.

Additive VS Multi

Starting off, we’re just going to quickly go over additive and multiplicative stats. You’ll see stat lines aspects things in your skill tree and your Paragon Board that either have a ‘+’ or an ‘X’ by them.

‘X’ will be better at 99% of the time. There are some instances where it’s not. But it’s safe to think that stats with an ‘X’ will be better than with a ‘+’.

How To Calculate Damage Increases In Diablo 4? - Damage and Defense Mechanics Explained

Damage Buckets

This is where people seem to get confused, Damage Buckets.

We have four main damage buckets in Diablo 4:

  • Main Stat
  • Crit Damage
  • Vulnerable Damage
  • Additive Damage

Each of these buckets multiplies with each other to get your final damage output. The most confusing bucket is the Additive Damage bucket. If it’s not Crit, Vul, or Main Stat 99 of the time, it goes into this bucket. So, things like core, close, healthy, injured, damage, and so on all go into this bucket.

This is because you have 0% close damage and you get 100% close damage somewhere does not mean you’re now going to double your damage against close targets. It gets put into the added a bucket with the other Additive Stats.

Keep in mind there are hidden stats that go into these buckets that will not show up on your stat screen. For example, Critical Damage against Crowd Control targets gets put into the Critical Damage bucket, but it does not show up as Critical Damage in my character screen.

It’s important that you balance out your damage buckets. If you have 600% Critical Damage but only 200% in your additive bucket, a 25% additive roll would be better than getting a 50% critical damage roll.

Also Read: Diablo 4 Shadowmancer Necromancer Build: Season 1 Endgame Guide

How To Calculate Damage?

How do we calculate our damage increases? I’ll be using my character stats in these examples.

So, we have 285% Critical Damage, 275% Vulnerable Damage, 800% in the Additive Damage, and 900 Dex in this current setup. You can calculate each of these buckets the same. When we’re representing these stats, we start from one for Critical Damage. The 285% would be represented as 3.85 when we’re doing our calculations.

Let’s say we get another 50% Critical Damage somewhere. We would now have the 335% Critical Damage versus the 285% we had before. We then take 4.35 divide that by 3.85. That would give us 1.129. That would mean that we get roughly a 13% damage increase. For our main stat, calculations 100 Main Stat equals 10% damage increase. So, when you’re calculating your Main Stat, make sure to convert it into the damage increase percentage and not the total amount of dexterity, strength, willpower, or whatever stat it may be.

So, say we have a crossbow with Crit Damage, Bone Damage, and Dex. And we’re trying to decide on what roll to get next. We can either go for a 70 all-stat damage roll or a 40% core damage roll. So, our Dex before is 900 and after it’ll be 970. So, we would take the after being a 1.97 and divide it by 1.9 to get a 1.036 or roughly a three and a half percent damage increase. For the additive, we would take the 800% before and the 840% after.

So, 9.4 divided by 9 gives us 1.044 or roughly a 4.4% damage increase. So, we have 3.5% versus 4.4%. If you are needing to get the all-stat roll to hit some Paragon node bonuses, it’s not going to be a huge damage loss.

To sum it up, you take what your stat will be after and divided it by what it was before. So, ‘X’ divided by ‘Y’ equals your damage increase.

Item Power

On to Diablo 4 Item power, how do we calculate our item power damage increases? Suppose you have an 818 sword and an 810 sword. Assuming both stat rolls are the same, you take the average of the damage per hit of both those weapons and divide the larger number by the smaller number, like we did with the damage buckets.

So, our 818 damage range is 989 to 1483. Add those numbers together. Divide them by two to get your average. Do the same with the other weapon. And then, we’ll take the average of both being 1236 for the 818 and 1198 for the 810. Divide 1236 by 1198 to get 1.0317 or roughly at three percent damage increase.


And lastly, are defenses. For our defenses, we have armor and resistances as well as damage reduction rolls.

Starting off with armor, this reduces physical damage taken from monsters on your level. What this means is that as a level gap between you and monsters increases, the amount of damage reduction you get from your armor is reduced.

In this chart, you can see how much armor you need in order to get the maximum damage reduction against X level of mobs.

how much armor you need in order to get the maximum damage reduction against X level of mobs

The maximum damage reduction you can receive from armor is 85%. So, if you are fighting mobs that are level 154, don’t go over 1300 armor as you’ll be overcapping.


Resistances are non-physical resistances damage reduction. So, for every two percent of a resistance stat, you get one percent damage reduction for that element.

If you get hit by a fire attack and you have 20% fire resistance, you have another 10% damage reduction against that attack. This additional 10% is then multiplied with all your other damage reduction rolls that apply to that attack if they were close distant poison, etc.

However, resistances don’t seem to be near is important in Diablo 4 as they are to a game like Path of Exile. I have pretty much completely ignored resistances, and it hasn’t seemed to affect me at all. Maybe down the road with seasons, resistances will become far more important. But for now, don’t stress and worry about how much resistance you have.

Damage Reduction

Finally, we’ll talk about damage reduction.

It’s important to note that damage reduction in Diablo 4 is multiplicative and not additive. So, you can never have a hundred percent damage reduction and be invincible.

If you have two sources of damage reduction, giving 50% damage reduction each your final damage reduction would be 75%. Suppose you get hit by an attack doing a hundred damage you would reduce that 100 to 50 and then you would further reduce the leftover 50 by another 50%, meaning you only take 25 damages. And if you had another 50% damage reduction roll somewhere, it would take the leftover 25 damage and put it to 12.5 and so on.

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