Level 95

Total Experience Required 5,849,894 [confirmed]

Level 100 progress: 85.7%

This is roughly:
Killing 19,500 people in Warzone, or...
Killing 19,898 people in Execution, or...
Killing 16,526 people in Wingman, or...
Scoring 4,178,496 points in Guardian, or...
Scoring 12,717,161 points in Annex, or...
Scoring 7,697,229 points in Submission.

Horde (TU4)

Completing 29,250 waves on Casual, or...
Completing 19,500 waves on Normal, or...
Completing 14,625 waves on Hardcore, or...
Completing 11,700 waves on Insane.

Or a combination of the above. Have fun!