How much time do you get for robbing a bank?

You can get up to life in prison.

That is a very serious federal crime. If you are considering it think about doing around 10 years in a federal prison whether you use a gun or not and it does not matter if anyone was injured.

It depends on a variety of factors that are absent from your question. Were you charged by the federal government or by the State? How many counts were you charged with? Were you charged with any other crimes? Are there enhancements or aggravating factors attached to your criminal charges? What is your criminal history? Bank Robbery is a very serious offense, and is generally treated as such. Depending on a variety of factors, and the prosecution's perspective of the case, you may be looking at no time (if you are acquitted or if there are issues that lead to dismissal) or up to multiple years in prison. You should absolutely have an attorney, whether court appointed or retained, to help you through the process if you are the individual who has been charged with bank robbery.

Depends on whether they charge it in state or federal court; whether there were more than 2 people involved; whether there were more than one robberies.

20 years