CDR calculation

I recently rolled 10% cool down to each one handed weapon I was using. I had 60.3% before I rolled and after with both equipped my CDR only went to 67%. I was expecting it to go around 72%. What am I missing here?

The calculation is done against 100% - your current cooldown, not at a 100% value. So 100% minus your current cooldown (60.3%) leaves 39.7% for the reductions to be calculated against. 10% of that (first weapon) is 3.97%, making your cooldown 64.27%, and 100%- 64.27 is 35.73. 10% of that for the second weapon calculation is 3.57%, so yes, although the flat value of the weapons is 20% cooldown combined, it is only worth +/- 7% because of the additional cooldown % you already have.

If you had no other cooldown anywhere, the first weapon would give you exactly 10% cooldown. The second one would give you 9%, because it would be reducing 10% of 90%.

I though the 10% would be against how much you already have as opposed to what was left. I see now. Thanks a bunch. That was disappointing. I was trying to get up to 75 ish so I could run without zodiac for epiphany on the TR build

It’s the same thing. But it is multiplicative instead of additive. The math works out the same.

My original thought was if I add 10% to the existing 60.3 it would Get me to 66.3 then another 10 would get me up to 72 ish. Instead it multiplies by the remainder of 100 - whatever cdr you currently have. Which in this case is only a 4% gain instead of 6%. Maybe I should just roll with area damage on both weapons