Sales tax
A sales tax is a tax, usually paid by the consumer at the point of purchase, itemized separately from the base price, for certain goods and services. The tax amount is usually calculated by applying a percentage
In mathematics, a percentage is a way of expressing a number as a fraction of 100 . It is often denoted using the percent sign, “%”, or the abbreviation “pct”. For example, 45% is equal to 45/100, or 0.45.Percentages are used to express how large/small one quantity is, relative to another quantity...

 rate to the taxable price of a sale.

A portion of the sale may be exempt from the calculation of tax, because sales tax laws usually contain a list of exemptions
Tax exemption
Various tax systems grant a tax exemption to certain organizations, persons, income, property or other items taxable under the system. Tax exemption may also refer to a personal allowance or specific monetary exemption which may be claimed by an individual to reduce taxable income under some...

. Laws governing the tax may require it to be included in the price (tax-inclusive) or added to the price at the point of sale.

Most sales taxes are collected from the buyer by the seller, who remits the tax to a government agency.