When it comes to predicting what a sentence will be for a specific crime, it can be very difficult. When a judge has determined that someone is guilty, the particular sentence can still vary greatly. This is because many individual details of a case can make it worthy of a higher or lower sentence. No two cases are exactly the same so sentencing can be difficult to predict.
When a judge assigns a sentence, they use federal sentencing guidelines that take into account different facts of the case to give the judge some idea of what the sentence should be. These guidelines give them a range of sentencing options. The judge then must take into account the individual facts of a case to determine where in the range the sentence should fall.