Experian: 1 to 100
Dun & Bradstreet: 0 to 100
Equifax Delinquency Score: 224-580
FICO SBSS: 0 to 300 (This is a blend of business and personal credit and is used primarily for SBA loans)
Head here for a detailed breakdown on how Experian, FICO SBSS, and Dun & Bradstreet determine these scoring ranges.