Sales Tax Calculator
Add sales tax to a pre-tax price, back the tax out of a tax-included total, or work out the rate from two prices. Set a quantity, apply an optional discount first, pick your currency, and see a full breakdown with the work shown step by step.
Formula
Worked example
A $100 purchase at 7.5% sales tax: tax = 100 × 0.075 = $7.50, so the total is $107.50. Reversed, a $107.50 tax-included total divides by 1.075 back to $100.00 net and $7.50 of tax.
How the Calculation Works
In the standard mode the calculator multiplies the pre-tax (net) amount by the tax rate written as a percentage, then adds that tax on top of the price to give the gross total. This is the add-on model used across the United States: tax is charged on top of the listed price, not embedded within it. When you set a quantity the price is multiplied first, and when you apply a discount it comes off before tax, which matches how most registers ring up a sale. The tool reports the taxable subtotal, the tax, the total and the effective tax paid per item so nothing is hidden.
Reverse modes: back tax out, or find the rate
The calculator does more than add tax on. Choose "Back tax out of a total" when a price already includes tax and you need the pre-tax figure, for an expense claim or an invoice: it divides the tax-included total by one plus the rate, so a 107.50 total at 7.5% comes back to a 100.00 net price and 7.50 of tax. Choose "Find the tax rate" when you know both the pre-tax price and the final price and want the percentage between them, useful for checking a receipt or reverse-engineering a quoted all-in price. Each mode shows the same clear breakdown and the steps behind it.
What Affects Your Tax Rate
Sales tax rates vary significantly by jurisdiction. In the United States rates are set at the state level and are frequently topped up by county and municipal surtaxes, so the combined rate in some locations passes 11%. The reference table below lists the base state rate and the maximum combined rate for several states. Other countries levy value-added tax (VAT) or goods and services tax (GST) on a national basis, with rates that typically run from 5% to 27%. Certain product categories such as groceries, prescription drugs or clothing may be taxed at a reduced rate or be fully exempt depending on local law.
Limitations to Keep in Mind
This calculator applies a single flat rate and does not model partial exemptions, product-category rates, tax holidays or tiered structures. The discount field applies before tax, which is the common US rule, but a few jurisdictions tax the pre-discount price, so check large purchases. The currency selector changes the displayed symbol only, it does not convert exchange rates, so convert a foreign price to your own currency first. Always verify the applicable combined rate with your state or country's revenue authority before filing or remitting tax.
Sample US state sales tax rates
| State | Base state rate | Max combined rate |
|---|---|---|
| California | 7.25% | 10.50% |
| Texas | 6.25% | 8.25% |
| New York | 4.00% | 8.875% |
| Florida | 6.00% | 7.50% |
| Tennessee | 7.00% | 9.75% |
| Louisiana | 4.45% | 11.45% |
| Colorado | 2.90% | 10.00% |
| Oregon | 0.00% | 0.00% |
| Delaware | 0.00% | 0.00% |
| Alaska | 0.00% | 7.00% |
Base state rate and the maximum combined rate once local and city taxes are added. Confirm your exact combined rate with the state revenue authority.
Frequently asked questions
How do I back the sales tax out of a tax-included price?
Divide the tax-included total by one plus the rate as a decimal. At 7.5%, divide the total by 1.075 to get the pre-tax price; the difference is the tax. For example a 107.50 receipt back-solves to 100.00 net and 7.50 tax. Switch this calculator to "Back tax out of a total" to do it automatically.
What is the average sales tax rate in the United States?
The average combined state and local sales tax rate in the US is roughly 7%, ranging from 0% in states like Oregon, Delaware and Montana to over 11% in parts of Louisiana and Tennessee. Your actual rate depends on the specific state, county and city where the sale happens, and the reference table below lists common state and maximum combined rates.
Is sales tax calculated before or after discounts?
In most US states sales tax is applied to the discounted (post-coupon) price rather than the original ticket price, so a discount lowers the tax too. This calculator applies the discount first and then taxes the reduced subtotal. Rules differ by state, and a few tax the pre-discount amount, so it is worth checking your local rule on large purchases.
What is the difference between sales tax and VAT?
Sales tax, used in the United States, is added on top of the listed price at the point of sale and collected only at the final retail stage. VAT, used in most other countries, is collected at each stage of production and distribution, but the end consumer sees a single tax-inclusive price. The total burden is similar; the collection mechanism differs.