Level 64

Total Experience Required 1,491,521

Level 100 progress: 21.85%

This is roughly the same as:

Killing 2,486 people in Warzone, or...
Killing 2,537 people in Execution, or...
Killing 2,107 people in Wingman, or...
Scoring 532,687 points in Guardian, or...
Scoring 1,621,219 points in Annex, or...
Scoring 981,264 points in Submission.

Horde (TU4)

Completing 3,729 waves on Casual, or...
Completing 2,486 waves on Normal, or...
Completing 1,865 waves on Hardcore, or...
Completing 1,492 waves on Insane.

Or a combination of the above. Have fun!