Quick answer
A $100 purchase in California at the 7.25% state rate plus a 1.5% local add-on costs $108.75, with $8.75 of sales tax. In Chicago the combined rate is 10.25%, so the same purchase costs $110.25. Five states charge no statewide sales tax at all.
How the Sales Tax & VAT works, step by step
Pick a system first: US sales tax or VAT. In the US, tax is added on top of the shelf price, so a $100 item at 8.75% costs $108.75 at the till. Under VAT, the shelf price already includes the tax, so a £120 price at 20% VAT contains £20 of tax and £100 of net value. The two systems answer different questions.
For US sales tax, pick your state and add your local rate. The state base is only the floor: California's 7.25% is the highest state rate, but local add-ons push combined rates past 10% in many cities. Chicago totals 10.25% on a 6.25% Illinois base, and the population-weighted average combined rate across the US was 7.53% in July 2026.
Five states have no statewide sales tax: Alaska, Delaware, Montana, New Hampshire and Oregon. Alaska is the exception within the exception, because its boroughs can levy local sales tax of up to about 7%. The other four charge nothing at state or local level, which is why cross-border shopping trips to Oregon and Delaware are a real business.
The VAT side works in two modes. Add mode charges tax on top of a net price, the way a B2B invoice works. Extract mode pulls the tax out of a tax-inclusive price, which is the shelf-price model: never calculate it as gross times the rate, because that overstates the tax. At 20% VAT, the tax inside £120 is £20, not £24.
Rates in the calculator are the published state bases and standard VAT rates, but exemptions and local changes move the real figure. Groceries are exempt from state sales tax in most states, clothing is exempt in a few, and local rates change several times a year. Confirm the exact rate for your ZIP code or country with the state revenue department before filing or quoting a price.
The formula
US add mode: tax = net amount times the combined rate; total = net amount plus tax. VAT add mode works the same way. VAT extract mode: net amount = gross amount divided by (1 plus the rate); tax = gross amount minus net amount. Combined US rate = state base rate plus local add-on.
Worked example — try it on the calculator above
Worked example: $100 in California, £120 under UK VAT
A $100 item in California at the 7.25% state rate plus a 1.5% local add-on is taxed at 8.75%, so the tax is $8.75 and the total is $108.75. The same $100 item in Chicago at 10.25% costs $110.25. Under UK VAT at 20%, a £120 shelf price contains £20 of tax: divide £120 by 1.20 to get the £100 net price, then subtract. Calculating it as £120 times 20% would wrongly give £24. A $100 item in Oregon, with no sales tax, costs exactly $100. The gap between the cheapest and dearest US checkout on the same $100 item is more than $10, which is why the state picker matters more than the arithmetic.
Frequently Asked Questions
Which states have no sales tax?
Five states have no statewide sales tax: Alaska, Delaware, Montana, New Hampshire and Oregon. Only Alaska lets local governments levy one, up to about 7% in some boroughs. The other four charge no sales tax at state or local level, though New Hampshire taxes meals and lodging at 8.5%.
Why is the tax on my receipt higher than the state rate?
Because most states let counties, cities and special districts add their own sales tax on top of the state base. Chicago's 10.25% is a 6.25% Illinois base plus county, city and transit add-ons. The calculator's local slider covers this: set it to your combined local rate.
How do I extract VAT from a price that includes it?
Divide the gross price by one plus the VAT rate, then subtract. At 20% VAT, £120 divided by 1.20 is £100 net, so the VAT is £20. Multiplying the gross price by 20% gives £24, which is wrong, because the 20% applies to the net price, not the gross one.
What is the average US sales tax rate?
The population-weighted average combined state and local rate was 7.53% in July 2026, according to the Tax Foundation. Louisiana has the highest average combined rate at 10.13%, and combined rates in some cities exceed 13%. Your exact rate depends on the address of the sale.
Estimates, not advice. This calculator provides educational estimates based on the inputs you enter and the assumptions shown on this page. It is not financial, tax or investment advice, and it cannot see your full situation. Verify important figures against official sources, and consider a qualified professional for decisions about your own money. See our Disclaimer and Methodology.