How does damage increasing affixes for specific skills affect the +damage% when you hover over an item? I don't see it change anything....for example I have boots that give disintegrate +12% damage but it says i'll lose 4.2% damage. If I switch to disintegrate then it doesn't change. Do I need to use a different calculator to see if it's a significant upgrade?

I don't think those affixes are taken into account by the game when showing you the tooltip. It also isn't shown in the skill tooltip for some reason (I think it would be aweosome if the skill tooltip updated that info too).

So basically, you have to take that into account yourself. If an affixincreases Disintegrate damage by 15%, you just take its damage (511%, right?) and then add 15% on top of that. Your Disintegrate would be roughly doing 587%~ damage now instead. Then you need to see if that extra 76% weapon-dmg/sec is better than the "sheet dps" loss (the 5-10k damage you lost when switching items).

I think in most cases, a small 1-3% damage loss is negligible against an extra 15% to a skill. It's particularly notable for Legendaries like Slorak's Madness (which add what, a whooping 30% bonus to a skill?).

Don't take my word for granted though, as I haven't researched a lot about the current skill theorycrafting.

If an affix on an item has an orange dot next to it, it is not taken into account when calculating your Damage, Toughness, or Healing. Think of the orange dot as saying "hey, pay attention to this, I'm not calculating it for you."

As for how they actually improve your damage (i.e., using Zero's example, whether it's 511% x 1.15 = 587% or 511% + 15% = 526%), I don't know.

yeah it's really hard to tell....i'm deciding between an old zuni boots and a new rare. the zuni boots has the 8% poison damage though...is that added to sheet dps?

So for example, if your paper doll damage is 100 and an item gives you +15% skill damage, then a 13% damage decrease would give you roughly 100 damage still while using that skill. Note that "damage decrease" is read as a positive number in the above formula, which I guess is a little confusing.

Another way to look at it is that your percentage change in damage using the skill is

(1 - damage decrease ) * (1 + skill increase)

Where both of those are written as decimal numbers, not percentages. So take a 10% skill increase and a 5% overall paper doll damage reduction, you would be doing (1-.05)*(1+.1)=1.045, or a 4.5% damage increase using that skill.

Someone correct me if my math is off or I'm not using the right assumptions.

Note that "damage decrease" is read as a positive number in the above formula, which I guess is a little confusing.
Another way to look at it is that your percentage change in damage using the skill is
(1 - damage decrease ) * (1 + skill increase)

An easier way to think of this is:

Your DPS Change = (1 + damage change in tooltip) * (1 + skill increase)

Obviously, the damage change can be negative. This is basically the same formula that trainRiderJ had, just without the damage decrease being a positive number.

Note that "damage decrease" is read as a positive number in the above formula, which I guess is a little confusing.
Another way to look at it is that your percentage change in damage using the skill is
(1 - damage decrease ) * (1 + skill increase)

An easier way to think of this is:

Your DPS Change = (1 + damage change in tooltip) * (1 + skill increase)

Obviously, the damage change can be negative. This is basically the same formula that trainRiderJ had, just without the damage decrease being a positive number.

So basically, you have to take that into account yourself. If an affix

increases Disintegrate damage by15%, you just take its damage (511%, right?) and then add 15% on top of that. Your Disintegrate would be roughly doing 587%~ damage now instead. Then you need to see if that extra 76% weapon-dmg/sec is better than the "sheet dps" loss (the 5-10k damage you lost when switching items).I think in most cases, a small 1-3% damage loss is negligible against an extra 15% to a skill. It's particularly notable for Legendaries like Slorak's Madness (which add what, a whooping 30% bonus to a skill?).

Don't take my word for granted though, as I haven't researched a lot about the current skill theorycrafting.

taken into account when calculating your Damage, Toughness, or Healing. Think of the orange dot as saying "hey, pay attention to this, I'm not calculating it for you."notAs for how they actually improve your damage (i.e., using Zero's example, whether it's 511% x 1.15 = 587% or 511% + 15% = 526%), I don't know.

skill increase = damage decrease / (1 - damage decrease)

So for example, if your paper doll damage is 100 and an item gives you +15% skill damage, then a 13% damage decrease would give you roughly 100 damage still while using that skill. Note that "damage decrease" is read as a positive number in the above formula, which I guess is a little confusing.

Another way to look at it is that your percentage change in damage using the skill is

(1 - damage decrease ) * (1 + skill increase)

Where both of those are written as decimal numbers, not percentages. So take a 10% skill increase and a 5% overall paper doll damage reduction, you would be doing (1-.05)*(1+.1)=1.045, or a 4.5% damage increase using that skill.

Someone correct me if my math is off or I'm not using the right assumptions.

Your DPS Change = (1 + damage change in tooltip) * (1 + skill increase)

Obviously, the damage change can be negative. This is basically the same formula that trainRiderJ had, just without the damage decrease being a positive number.