The amound of EXP necessary for the next Level-Up increases by 100 per Level.
Every 10th Level the amount for the next Level-Up increases by additional 100 EXP for all following Level.
F.e. to reach Lvl 3 you need 200 EXP. For the next leven you need 100 EXP more. That means you will need 300 EXP to reach Lvl 4 (200 + 100
There is no max. Level.