Sales tax percentage is the percentage rate applied to the sale of goods or services, to be paid in addition to the purchase price to contribute to the operation of state, city, or local government functions.
Sales tax is a portion of money paid to the government, usually expressed and calculated as a percentage of the total sale price on goods and services.
Typically, the seller collects sales tax at the time of sale, then makes quarterly payments to the appropriate government agency.
You may look up state and local tax rates here.