How to Calculate Price With Sales Tax & Gratuity

When you go out to a restaurant to eat, you typically have to add both sales tax and a gratuity for the server to the price of the bill. The sales tax will always be added to your bill for you. Depending on the size of your party, the restaurant may add the gratuity automatically. For example, a restaurant may add a 19 percent gratuity if you have eight or more in your party. Otherwise, it is up to you to add the gratuity. To figure the total price, you need to know the percentages for both the sales tax and the gratuity.

Add the sales tax percentage to the gratuity percentage. For example, if the sales tax rate equals 5.6 percent and the gratuity equals 19 percent, the total to add to the bill equals 24.6 percent.

Divide the sum of the sales tax percent and the gratuity percent by 100 to convert to a decimal. In this example, divide 24.6 percent by 100 to get 0.246.

Multiply the result by the amount of your bill to find what the sales tax and gratuity add to the bill. For example, if the bill is $84, multiply $84 by 0.246 to get $20.66.

Add the cost of the gratuity and sales tax to the bill to calculate the total price. In this example, add $20.66 to $84 to get $104.66.