The Dodge Chance % shown under your character sheet details is derived directly from your Dexterity. The Dodge amount per dexterity point no longer varies based on how many points you have, rather by the level that you are:
At level 70, the relationship is:
Dexterity / 217 = Dodge %, rounded to the nearest 0.X%
I have tested this from 77 to 8096 dexterity in 5 dexterity increments. This means to get 100% dodge chance you'd need 21700 dexterity! (50% Dodge at 10850 Dex - That's a lot of Paragon Levels)
At level 1, the relationship is:
Dexterity / 2.2 = Dodge %, rounded to the nearest 0.x%
Here are a couple more levels:
Level 2: Dex/2.6
Level 3: Dex/3
Level 4: Dex/3.4
Level 5: ~ Dex/3.62
Level 6: ~ Dex/3.86
Level 7: ~ Dex/4.16
Level 9: ~ Dex/4.9
Level 11: ~ Dex/6.32
ETC.
The important one is level 70, because that's where you'll spend the most time.