Level 65

Total Experience Required 1,576,813

Level 100 progress: 23.1%

This is roughly the same as:

Killing 2,629 people in Warzone, or...
Killing 2,682 people in Execution, or...
Killing 2,228 people in Wingman, or...
Scoring 563,148 points in Guardian, or...
Scoring 1,713,928 points in Annex, or...
Scoring 1,037,377 points in Submission.

Horde (TU4)

Completing 3,943 waves on Casual, or...
Completing 2,629 waves on Normal, or...
Completing 1,972 waves on Hardcore, or...
Completing 1,577 waves on Insane.

Or a combination of the above. Have fun!