Add sales tax to a price, or work backward from a total to find the pre-tax price and the tax amount.
Sales tax is a percentage added to the price of most goods and services at the point of sale. To add tax to a price, multiply the price by the tax rate and add that to the original price. To find the pre-tax price from a total that already includes tax, divide the total by 1 plus the tax rate as a decimal.
Unlike a national VAT, sales tax in the US is set by state and often stacked with county and city rates, so the actual rate at checkout can differ block to block. A handful of states charge no state sales tax at all, while some combined local rates climb past 9-10%. Always check your local combined rate rather than assuming a single national figure — this calculator just does the math once you know that number.
This tool doesn't account for tax-exempt categories (groceries and prescription medication are commonly exempt in many states), tax holidays, or origin-based versus destination-based sourcing rules for online purchases. It's a straightforward percentage calculator, not a tax-compliance tool.
To add tax to a price, enter the pre-tax amount and your local tax rate, and the calculator returns the tax amount along with the final total. To work backward from a total that already includes tax, switch modes and enter the total amount along with the tax rate — the tool returns the original pre-tax price and the tax portion separately. This backward calculation is especially useful for reviewing receipts or figuring out the actual cost of an item before tax was applied.
In the United States, sales tax isn't set at a single national rate — it's a patchwork of state, county, and city-level taxes that stack together, meaning the combined rate can genuinely differ between two addresses just a few miles apart. Some states charge no state-level sales tax at all, relying instead on other revenue sources like income or property tax, while others combine state and local rates that add up to well over 9-10% in some areas. Because of this variation, there's no single "correct" rate to plug in without knowing the specific jurisdiction where a purchase is taking place.
Many states carve out exemptions for certain categories of goods, most commonly groceries, prescription medications, and sometimes clothing below a certain price threshold. These exemptions exist largely for policy reasons — taxing essential items like food can disproportionately affect lower-income households, so many states choose to exempt them entirely or tax them at a reduced rate. Because exemption rules vary significantly by state and even by specific product category, this calculator simply applies whatever flat rate you enter — it's up to you to know whether tax actually applies to the specific item you're calculating.
Several US states hold periodic "sales tax holidays" — typically brief windows, often timed around back-to-school shopping or emergency preparedness season — during which certain categories of goods are temporarily exempt from sales tax entirely. These holidays are set by individual state legislatures and vary in timing, duration, and which product categories qualify. If you're shopping during one of these windows, remember to check whether your specific purchase actually qualifies before assuming standard tax rates apply, since qualifying categories are often narrowly defined (for example, clothing under a certain price point, or specific school supplies).
Online and remote sales add another layer of complexity to sales tax calculations. Origin-based tax rules charge sales tax based on the seller's location, while destination-based rules charge tax based on the buyer's location — and different states use different approaches for in-state transactions. For purchases shipped across state lines, tax is generally determined by the buyer's location and whether the seller has sufficient business presence ("nexus") in that state, following rules that became significantly more standardized after a 2018 US Supreme Court ruling on interstate sales tax collection. This calculator focuses purely on the percentage math — determining which rate actually applies to a specific transaction requires checking the relevant state and local tax authority.
How do I find my exact local sales tax rate? Check your state's department of revenue website, or look at a recent receipt from a local purchase, since combined state-county-city rates are usually shown as a single line item at checkout.
Why is my receipt's tax amount slightly different from this calculator's result? Rounding conventions can vary slightly by retailer or point-of-sale system, and some jurisdictions round tax per line item rather than on the total, which can create small differences from a single combined calculation.
Does this calculator handle VAT for countries outside the US? The same percentage math applies, though VAT systems often work differently — VAT is typically included in displayed prices already, rather than added at checkout the way US sales tax usually is.
Can I use this for calculating tax on a large purchase like a car? Yes, the math is the same, though vehicle purchases sometimes involve additional fees or different tax treatment (like trade-in credits) that a simple percentage calculator won't capture — check with your local DMV or dealer for exact figures.
Are all goods and services taxed at the same rate? No — many jurisdictions exempt or reduce tax on categories like groceries, prescription medication, or clothing, so the standard combined rate doesn't apply universally to every purchase.
Do online purchases get taxed at my local rate or the seller's rate? In most cases within the US, online retailers now charge sales tax based on the buyer's shipping address rather than the seller's location, following changes in tax law over the past several years.
Last reviewed by Mehmed on July 11, 2026.