Level 60

Total Experience Required 1,182,611

Level 100 progress: 17.33%

This is roughly the same as:

Killing 1,972 people in Warzone, or...
Killing 2,012 people in Execution, or...
Killing 1,671 people in Wingman, or...
Scoring 422,362 points in Guardian, or...
Scoring 1,285,447 points in Annex, or...
Scoring 778,034 points in Submission.

Horde (TU4)

Completing 2,957 waves on Casual, or...
Completing 1,972 waves on Normal, or...
Completing 1,479 waves on Hardcore, or...
Completing 1,183 waves on Insane.

Or a combination of the above. Have fun!