Speed Calculations
Your final cast and recast values depend on your skill or spell speed, your level, and buffs. Due to the complexity of this formula, it has been partitioned into three parts. It is one of the few formulas to include roundup.
Steps
Step 1: Milliseconds
GCDm = ⌊ ( 1000 - ⌊ 130 × ( SS - LevelModLv, SUB ) / LevelModLv, DIV ⌋ ) × ActionDelay / 1000 ⌋
ActionDelay must be written in milliseconds. A 2.5 GCD, is equivalent to 2500 milliseconds.
Step 2: Centiseconds
A = ⌊ ( 100 - Arrow ) × ( 100 - Type I ) / 100 ⌋ × ( 100 - Haste ) / 100 ⌋ - Fey Wind ⌋
B = ( 100 - Type II ) / 100
GCDc =⌊ ⌈ A × B ⌉ × GCDm / 100 ⌋ × Riddle of Fire / 1000 ⌋ × Astral_Umbral / 100 ⌋
Riddle of Fire is (100) when inactive and (115) when active. Astral_Umbral is (100) when inactive and (50) when active. Haste is specific to speed buffs from instances such as Palace of the Dead. Type I and Type II skills variables are listed in the table below. If none of the buffs listed are present, then Type I and Type II become (0).
Step 3: Seconds
GCD = GCDc / 100