Level 45

Total Experience Required 440,381

Level 100 progress: 6.45%

This is roughly the same as:

Killing 734 people in Warzone, or...
Killing 749 people in Execution, or...
Killing 623 people in Wingman, or...
Scoring 157,279 points in Guardian, or...
Scoring 478,675 points in Annex, or...
Scoring 289,725 points in Submission.

Horde (TU4)

Completing 1,101 waves on Casual, or...
Completing 734 waves on Normal, or...
Completing 551 waves on Hardcore, or...
Completing 441 waves on Insane.

Or a combination of the above. Have fun!