It will depend upon your resort.
Most of Walt Disney World is in Orange County, where the sales tax rate is 6.5% and the hotel tax rate works out to 12.5% (6.5% sales tax + 6% resort tax).
Disney’s All Star Resorts are in Osceola County, where the sales tax rate is 7% and the resort tax is 6%, so the hotel tax rate at those three hotels is 13%.