How to Calculate Sales Tax and Discounts Manually

Whether you are shopping at a mall or running a small business, calculating tax and discounts is a daily necessity. Here is the simple math to help you stay on budget.

Calculating Sales Tax

To find the total price including tax, you multiply the original price by the tax rate (as a decimal) and add it to the original price.

Total = Price + (Price × Tax Rate)

Example: A $50 item with 8% tax.
$50 × 0.08 = $4. Total is $54.

Calculating a Discount

To find a sale price, subtract the discount from the original price.

Sale Price = Original Price × (1 - Discount Rate)

Example: A $100 coat at 30% off.
$100 × (1 - 0.30) = $70.

For bigger lists and faster results, use our Percentage Calculator.