Level 69

Total Experience Required 1,953,486

Level 100 progress: 28.62%

This is roughly the same as:

Killing 3,256 people in Warzone, or...
Killing 3,323 people in Execution, or...
Killing 2,760 people in Wingman, or...
Scoring 697,674 points in Guardian, or...
Scoring 2,123,355 points in Annex, or...
Scoring 1,285,189 points in Submission.

Horde (TU4)

Completing 4,884 waves on Casual, or...
Completing 3,256 waves on Normal, or...
Completing 2,442 waves on Hardcore, or...
Completing 1,954 waves on Insane.

Or a combination of the above. Have fun!