Riot Combat MathLinear Cast Frequency Curve
League of Legends Ability Haste to CDR Calculator
Understand how Ability Haste scales non-linearly with Cooldown Reduction percentage (CDR = AH / (AH + 100)). Calculate exact cooldown seconds for your champion's Q, W, E, R and summoner spells.
Haste Stats & Spell Cooldown
Total Ability Haste (AH)65 AH (39.4% CDR)
Example: Blitzcrank Hook (20s), Ahri Charm (12s), Lux Ult (60s), Flash (300s).
Ability Haste vs Effective CDR% Curve
CDR: 39.4%0 AH (0% CDR)100 AH (50% CDR)X: Ability Haste | Y: Equivalent CDR %
Effective CDR
39.4%
Equivalent legacy CDR
New Cooldown
7.27 s
-4.73s saved
Casts Per Minute
8.2 / min
+65% more casts
Flash Cooldown
300 s
Summoner spell
Why Riot Replaced CDR with Ability HasteLinear Scaling Principle
Old CDR grew exponentially in value (going from 30% to 40% CDR was worth far more than 0% to 10%). Ability Haste scales linearly with cast frequency: every 1 point of Ability Haste allows you to cast your abilities 1% more often over a sustained fight.