Level 79

Total Experience Required 3,163,200

Level 100 progress: 46.34%

This is roughly the same as:

Killing 5,272 people in Warzone, or...
Killing 5,380 people in Execution, or...
Killing 4,468 people in Wingman, or...
Scoring 1,129,715 points in Guardian, or...
Scoring 3,438,261 points in Annex, or...
Scoring 2,081,053 points in Submission.

Horde (TU4)

Completing 7,908 waves on Casual, or...
Completing 5,272 waves on Normal, or...
Completing 3,954 waves on Hardcore, or...
Completing 3,164 waves on Insane.

Or a combination of the above. Have fun!