Level 70

Total Experience Required 2,057,255 [confirmed]

Level 100 progress: 30.14%

This is roughly:
Killing 6,858 people in Warzone, or...
Killing 6,998 people in Execution, or...
Killing 5,812 people in Wingman, or...
Scoring 1,469,468 points in Guardian, or...
Scoring 4,472,294 points in Annex, or...
Scoring 2,706,915 points in Submission.

Horde (TU4)

Completing 10,287 waves on Casual, or...
Completing 6,858 waves on Normal, or...
Completing 5,144 waves on Hardcore, or...
Completing 4,115 waves on Insane.

Or a combination of the above. Have fun!