Level 56

Total Experience Required 926,536

Level 100 progress: 13.57%

This is roughly the same as:

Killing 1,545 people in Warzone, or...
Killing 1,576 people in Execution, or...
Killing 1,309 people in Wingman, or...
Scoring 330,906 points in Guardian, or...
Scoring 1,007,105 points in Annex, or...
Scoring 609,564 points in Submission.

Horde (TU4)

Completing 2,317 waves on Casual, or...
Completing 1,545 waves on Normal, or...
Completing 1,159 waves on Hardcore, or...
Completing 927 waves on Insane.

Or a combination of the above. Have fun!