Sales Tax Calculator
Instantly calculate the sales tax owed on any purchase given a tax rate percentage. Useful for shoppers verifying receipts and retailers setting final prices at checkout.
About this calculator
Sales tax is a percentage-based levy applied to the pre-tax purchase amount. The formula is: Sales Tax = amount × (taxRate / 100). Dividing the rate by 100 converts a percentage (e.g., 8%) into a decimal multiplier (0.08). The total amount paid by the customer is then: Total = amount + Sales Tax = amount × (1 + taxRate / 100). Tax rates vary by country, state, and even product category — groceries are exempt in many US states, while luxury goods may carry higher rates. Knowing the exact tax amount helps consumers budget accurately and helps businesses remit the correct amount to tax authorities. Always confirm the applicable rate for your jurisdiction, as this calculator uses whatever rate you enter.
How to use
You're buying a laptop priced at $850 in a state with an 8.5% sales tax. Enter 850 in Purchase Amount and 8.5 in Tax Rate. The calculator computes: Sales Tax = 850 × (8.5 / 100) = 850 × 0.085 = $72.25. Your total at the register would be $850 + $72.25 = $922.25. Now check a $25 book in the same state: 25 × 0.085 = $2.13 tax, so $27.13 total. This makes it easy to compare after-tax prices across different items or jurisdictions before you commit to a purchase.
Frequently asked questions
How do I calculate sales tax from a total price that already includes tax?
To extract the tax from a tax-inclusive total, use the reverse formula: Sales Tax = Total − (Total / (1 + taxRate / 100)). For example, if your receipt shows $108.50 and the tax rate is 8.5%, the pre-tax amount is $108.50 / 1.085 = $100, and the tax is $8.50. This is called 'backing out' the tax and is useful when a price tag already includes tax but you need to report the tax portion separately for accounting purposes.
What is the difference between sales tax and VAT?
Sales tax is collected only at the final point of sale to the consumer, and the full tax amount appears as a single line on the customer's receipt. VAT (Value Added Tax) is collected at every stage of the supply chain — manufacturers, wholesalers, and retailers each pay and reclaim VAT on their portion of the value added. The end consumer bears the same economic burden under both systems, but VAT creates a paper trail at each production stage that reduces tax evasion. The US uses sales tax; most of Europe and many other countries use VAT.
Why do sales tax rates differ between states and cities?
Sales tax rates in the US are set independently by states, counties, and municipalities, so the combined rate can vary even between neighbouring towns. States use sales tax as a major revenue source to fund public services like schools, roads, and emergency services, and each jurisdiction sets its own rate based on budget needs and political priorities. Some states exempt necessities like groceries or prescription drugs to reduce the burden on lower-income residents. When you shop online, the applicable rate is typically determined by your delivery address (destination-based sourcing), which is why the same item can have different tax totals depending on where it's shipped.