# Confusion calculating spell damage

#### Grobyc

##### Diabloii.Net Member
Confusion calculating spell damage

I've noticed that the numbers don't turn out like they are supposed to. Meteor for example, with all synergies and Fire Mastery, it would give 363% damage increase, a level 20 Meteor gives 1k damage. That would make it ~3.6k damage. But in actuality, when you check your damage, it's far more than that, so how do they calculate it?

#### wookie919

##### Diabloii.Net Member
You can't add the percentages together if they are applied one after the other.

The bonus from the synergies apply first, then the damage bonus from the fire mastery is applied.

e.g.

Level 20 Meteor without any synergies = 869 to 927
1 point in firebolt gives: (869 * 1.05) to (927 * 1.05) = 912 to 973
1 point in FM then gives: (912 * 1.3) to (973 * 1.3) = 1186 to 1265

(Damage numbers shown on screen are rounded down, but during calculation the numbers are not rounded, so 912 * 1.3 really is 912.45 * 1.3.)

I hope that's clear.

#### Grobyc

##### Diabloii.Net Member
:scratch:

level 20 Meteor = 955-1019 damage
With level 20 Firebolt and Fireball (955 * 3) to (1019 * 3) = 2865 to 3057
With level 17 Fire Mastery (2865 * 2.42) to (3057 * 2.42) = 6933 to 7397

Those should be the correct numbers according to what you have given me. However 6308 to 6730 is the damage the game has given me. :scratch:

#### wookie919

##### Diabloii.Net Member
Hi, not sure where you got the following from:

"level 20 Meteor = 955-1019 damage"

Level 20 Meteor alone should be 869 to 927 as stated in previous post.

Using 869 and 927, you will find that the numbers shown on your screen are correct.

869 * 3 * 2.42 = 6308.94
927 * 3 * 2.42 = 6730.02

#### wookie919

##### Diabloii.Net Member
Grobyc said:
Arreat Summit is often wrong.

#### Grobyc

##### Diabloii.Net Member
wookie919 said:
Arreat Summit is often wrong.
Hmm, I never knew that. So I got it down, thanks .

#### RTB

##### Diabloii.Net Member
wookie919 said:
Arreat Summit is often wrong.
The values listed there include the synergy bonus from pre-reqs. Don't use them for base skill dmg.