Federal felonies in the United States are divided into six Criminal History Categories and assigned an offense level from one to 43, according to CriminalDefenseLawyer.com, published by Nolo. Classifications for state felonies vary by state, with some states assigning a "class" as a letter or a "level" as a number, while other states have no classifications, and some have a mixture of classified and unclassified felonies.
An offense level is assigned based on the severity of the crime, with more severe crimes receiving a higher level and a longer prison sentence, states FederalCharges.com. A federal felony is classified into a Criminal History Category based upon prior convictions of the defendant using a points system. For example, a prior conviction with a 60-day sentence or less is allotted one point, while a conviction with a 13-month or longer sentence is allotted three points. The total number of points determines the Criminal History Category from Roman numeral one to six, with Category I containing the least amount of points. The higher the category, the longer the sentence.
Some states classify state felonies assigning a class from A to D, a level from one to six, a degree or a Roman numeral, according to CriminalDefenseLawyer.com. For example, Maine identifies felonies as Class A, B or C, while Ohio classifies felonies as first, second, third, fourth or fifth degree. Class A or Level One felonies are considered the most severe. Some states, such as Massachusetts, identify felonies by crime, while others, such as Kansas, use a grid system.