There is not enough information here to answer. His attorney should be able to figure it out. It mostly depends on how much time he was looking at with the initial charge(s). You probably don't have that information and quite honestly, he may not know either. So much depends on what he was found guilty of and of his previous criminal history.
There are a lot of different factors that have to be considered before providing an estimate about what could happen. A felony probation violation could result in county jail time or state prison. Some of the variables to be considered involve the probationers progress on probation, number of violations that have occurred while on probation, and the reason for the violation. If there is a new charge accompanying the probation violation, then there is also potential for increased punishment apart from the probation violation. Before giving an assessment as to "how much time" an individual in this situation is looking at, I would suggest a free consultation.
If the probation sentence was suspended, then the suspended sentence. If the revocation hearing is a parole hearing, then add a year. Add another year for the misdemeanor. That's a good guess based upon the facts provided. May be less, may be more. Good luck.
The response above is not intended as legal advice since it’s impracticable to provide thorough, accurate advice based upon the query without additional details. It is highly recommended that one should seek advice from a criminal defense attorney licensed in your jurisdiction by setting up a confidential meeting. Moreover, this response does not constitute the creation of an attorney-client relationship since this message is not a confidential communication because it was posted on a public website, thereby publicly disclosing the information, which is another reason to setup a confidential meeting with an attorney.
You to supply more information about the underlying felony. Clearly, the misdemeanor has a max term of one year, but its unclear what he's "facing" without more detail, most of which shouldn't be shared in a public forum. Best plan is to consult an attorney privately or discuss the matter with his current attorney, if he has one.