About the Sales Tax Calculator
The Sales Tax Calculator does two jobs in one place. In Add mode it takes a pre-tax price and a tax rate and shows you the sales tax and the final total — handy for budgeting a purchase, checking a quote, or ringing up an order. In Remove mode it works backward: give it a tax-inclusive total and it tells you the original pre-tax price and how much of the total was tax. That reverse calculation trips a lot of people up, because you can't just subtract the tax percentage from the total — this tool handles it correctly. You can type any combined rate you like, or pick a state's base rate to get started.
Formula Used
Adding sales tax to a price is a simple markup:
Sales Tax = Pre-Tax Price × (Rate ÷ 100)
Total = Pre-Tax Price + Sales Tax
Removing sales tax from a tax-inclusive total requires dividing, not subtracting, because the tax was originally charged on the smaller pre-tax amount:
Pre-Tax Price = Total ÷ (1 + Rate ÷ 100)
Sales Tax = Total − Pre-Tax Price
Worked Example (Adding Tax)
You're buying a $100 item in a city with an 8.25% combined sales tax rate:
Sales tax = 100 × (8.25 ÷ 100) = $8.25
Total = 100 + 8.25 = $108.25
So the item costs $108.25 at the register, of which $8.25 is tax.
Worked Example (Removing Tax)
Now suppose a receipt shows a $108.25 total and you know the rate was 8.25%, and you want the pre-tax price:
Pre-tax price = 108.25 ÷ (1 + 8.25 ÷ 100)
= 108.25 ÷ 1.0825 = $100.00
Sales tax = 108.25 − 100.00 = $8.25 Notice that subtracting 8.25% of $108.25 would give $8.93 — the wrong answer. Dividing by 1.0825 is the correct way to back the tax out.
Common Combined Rates by Purchase
Here's what a few rates add to common purchase amounts, so you can sanity-check the tax on a bill:
| Pre-Tax Price | At 6% | At 8% | At 10% |
|---|
| $25 | $26.50 | $27.00 | $27.50 |
| $100 | $106.00 | $108.00 | $110.00 |
| $500 | $530.00 | $540.00 | $550.00 |
| $1,000 | $1,060.00 | $1,080.00 | $1,100.00 |
How U.S. Sales Tax Actually Works
There is no national sales tax in the United States. Instead, 45 states and the District of Columbia levy a statewide rate, and thousands of counties, cities, and special districts stack their own local taxes on top. That's why your combined rate — the number that actually matters on a receipt — can differ from one town to the next within the same state. The state presets in this calculator are the state base rates; you'll usually need to add local tax to get the true combined rate for a specific address.
Origin vs. Destination Sourcing
For a purchase made in a physical store, tax is charged at the store's location. For online and shipped orders, most states use destination-based sourcing: the rate is set by where the item is delivered, not where the seller sits. Since the Supreme Court's 2018 South Dakota v. Wayfair decision, most online retailers must collect sales tax based on the buyer's location once they cross a sales threshold in that state. A handful of states use origin-based sourcing for their own in-state sellers.
Tips & Common Mistakes
- Don't subtract the percentage to remove tax. Subtracting 8% of a tax-inclusive total overstates the pre-tax price. Always divide by (1 + rate). This tool's Remove mode does it for you.
- Use the combined rate, not just the state rate. Local taxes commonly add 1–5%. A "6%" state can be 9%+ at the register in a big city.
- Check whether the item is exempt. Many states don't tax groceries or prescription drugs, or tax them at a lower rate — set the rate accordingly.
- Round only at the end. Rounding each line's tax separately can put a receipt off by a penny or two versus taxing the subtotal once.
- Remember use tax. If a seller didn't charge sales tax on something you use in your state, you may owe use tax at the same rate directly to your state.
Disclaimer
This calculator is a general estimating tool, not tax advice. Actual sales tax depends on the exact combined rate for the location, product-specific exemptions, and rules that change over time. Confirm the correct rate with the seller or your state's department of revenue. For income taxes, see the Income Tax Calculator; to work out a price markup or margin, use the Markup Calculator; and for any straight percentage math, the Percentage Calculator.
Frequently Asked Questions
How do you calculate sales tax on a purchase?Multiply the pre-tax price by the sales tax rate written as a decimal, then add it to the price. For a $50 item at an 8% rate: 50 × 0.08 = $4.00 in tax, so the total is $54.00. To get the decimal, divide the percentage rate by 100 (8% ÷ 100 = 0.08). This calculator does it for you and also shows the running total, so you can check a receipt or budget for tax before you buy.
How do I remove sales tax from a total to find the original price?Divide the tax-inclusive total by 1 plus the tax rate as a decimal. If a receipt shows $108.25 and the rate is 8.25%, the pre-tax price is 108.25 ÷ 1.0825 = $100.00, and the tax was $8.25. Do not simply subtract 8.25% of the total — that overstates the discount, because the percentage was originally applied to the smaller pre-tax figure, not the total. Switch this calculator to "Remove sales tax" mode to do it correctly.
What sales tax rate should I use?Use the combined rate for the location where the sale takes place — the state base rate plus any county, city, and special-district taxes. The state presets in this tool are base state rates only; most places add local taxes on top, so the real combined rate is often 1–5 percentage points higher. Your receipt, or your state's department of revenue lookup tool by ZIP code, will give you the exact combined rate.
Which states have no sales tax?Five states have no statewide general sales tax: Alaska, Delaware, Montana, New Hampshire, and Oregon (an easy way to remember them is "NOMAD"). Alaska has no state sales tax but allows local municipalities to levy their own, so some Alaskan towns still charge sales tax. In the other four, most everyday purchases are tax-free, though specific excise taxes on items like gasoline, lodging, or prepared food can still apply.
Is sales tax based on where I live or where I buy?For in-store purchases, sales tax is charged at the point of sale — the store's location. For online and shipped orders, most states use destination-based sourcing, meaning the rate is based on where the item is delivered (your address), not where the seller is. A few states use origin-based sourcing for in-state sellers. Since the 2018 Wayfair ruling, most online retailers must collect sales tax based on the buyer's location.
Do all products get taxed at the same rate?No. Many states exempt or reduce the rate on necessities like groceries, prescription drugs, and sometimes clothing, while taxing prepared food, electronics, and general merchandise at the full rate. Some items carry extra excise taxes. Because product-level rules vary widely by state, this calculator uses a single rate you enter — set it to the specific combined rate that applies to the item and location in question.
What is the difference between sales tax and VAT?Sales tax is charged once, at the final retail sale to the consumer, and is added on top of the listed price — common in the United States. A value-added tax (VAT) is collected in stages throughout the supply chain and is usually already baked into the displayed price — common in Europe and much of the world. To find the tax portion inside a VAT-inclusive price, use this calculator's "Remove sales tax" mode with the VAT rate.
Is sales tax the same as an effective or use tax?Sales tax is collected by the seller at purchase. Use tax is the mirror image: if you buy something without paying sales tax (for example, from an out-of-state seller that didn't collect it) and use it in your state, you may owe an equivalent use tax directly to your state. The rate is generally the same as your local sales tax rate, so this calculator works for estimating either one.