THE FOLLOWING CALCULATOR WILL GIVE YOU AN IDEA OF WHAT YOUR backoff sets should be based on  what you did  for your top set. Keep in mind if you went to heavy on your top set, these numbers  may be too high due to your fatigue. If you went too light on your top set, these numbers will likely be too low. Consider them to be approximations and averages, somewhere in the middle. Adjust your backoff sets accordingly.