Level 100

Total Experience Required 6,825,825 [confirmed]

Level 100 progress: 100%

This is roughly:
Killing 22,753 people in Warzone, or...
Killing 23,218 people in Execution, or...
Killing 19,282 people in Wingman, or...
Scoring 4,875,590 points in Guardian, or...
Scoring 14,838,750 points in Annex, or...
Scoring 8,981,349 points in Submission.

Horde (TU4)

Completing 34,130 waves on Casual, or...
Completing 22,753 waves on Normal, or...
Completing 17,065 waves on Hardcore, or...
Completing 13,652 waves on Insane.

Or a combination of the above. Have fun!