Sales Tax Calculator
Add sales tax to a price or back it out of a total. Enter the amount and your combined tax rate to see the tax and the total.
Enter your combined state + local rate. U.S. sales tax rates vary by city and county.
How to use this calculator
Choose add tax to price or remove tax from total, then enter the amount and your sales tax rate. The calculator shows the tax amount and the resulting figure — either the final price with tax included, or the original pre-tax price if you are backing out a tax that is already embedded.
If you are not sure of your rate, the state pages below pre-fill the average combined rate for your state. For exact accuracy, look up your specific address on your state's department of revenue website, since city and county rates vary within each state.
How sales tax works
Sales tax is a consumption tax collected at the point of sale. The seller collects it from the buyer and remits it to the state (and local) government. In the United States, sales tax is administered at the state level rather than federally, which is why rates differ dramatically from one place to the next.
The rate you pay is typically a combined rate made up of the base state rate plus any county, city, or special district rates that apply to your purchase location. A state might have a 6% statewide rate, but a city within that state may add another 2%, making your effective rate 8%.
Not everything you buy is taxable. Most states exempt prescription medications and many exempt unprepared groceries. Some states exempt clothing under a certain price, and many run annual "tax holidays" on things like back-to-school supplies. The rules vary by state and change over time, so when in doubt, check your state's revenue department.
Worked example: adding tax
You are buying a piece of furniture priced at $450 in a location with a combined sales tax rate of 8.5%:
- Tax amount: $450 × 0.085 = $38.25
- Total at checkout: $450 + $38.25 = $488.25
Enter $450 as the price and 8.5% as the rate in "add tax" mode and the calculator returns $38.25 in tax and a $488.25 total instantly.
Worked example: removing tax
You have a receipt showing a total of $488.25 and you need to know the pre-tax price (perhaps for an expense report that requires you to separate the tax):
- Pre-tax price: $488.25 ÷ 1.085 = $450.00
- Tax paid: $488.25 − $450.00 = $38.25
Switch to "remove tax" mode, enter $488.25 and 8.5%, and the calculator works backwards to $450 pre-tax. This is especially useful when a receipt does not itemize the tax separately.
How to interpret your result
The result shows the tax amount and the missing half of the equation (total or pre-tax price, whichever you did not enter). Both figures are exact given the rate you provided. Keep in mind that the rate you use drives everything — a half-point difference in rate on a $500 purchase changes the tax by $2.50, which may matter for business accounting.
Common mistakes to avoid
- Using the state rate instead of the combined rate. The state rate is almost always just a floor. Add county and city rates for your actual location to get the combined rate you will pay at checkout.
- Multiplying the total by the rate to find the tax. If you already paid a tax-inclusive price and multiply it by the rate, you get a slightly wrong answer — the tax is on the pre-tax price, not the total. Use the divide-by-(1 + rate) method instead.
- Assuming all items in your cart are taxable at the same rate. Some items (groceries, prescriptions) may be exempt or taxed at a different rate within the same transaction. Retailers calculate tax line by line; this calculator handles a single rate per calculation.
- Forgetting online purchases may also be taxable. Most large online retailers now collect sales tax for every state that requires it. Do not assume an online price is tax-free — the tax may be added at checkout based on your shipping address.
The formula
Add tax: Total = Price × (1 + rate) · Remove tax: Price = Total ÷ (1 + rate)
Tax amount (add mode) = Price × rate
Tax amount (remove mode) = Total − (Total ÷ (1 + rate))
Sales tax by state
Sales tax rates vary widely across the US. Pick your state for its average combined rate, pre-filled and ready to use:
How we calculate this
To add tax we multiply the price by your rate; to remove it we divide the tax-inclusive total by 1 plus the rate. The by-state pages pre-fill each state's average combined rate (population-weighted state + local) as published by the Tax Foundation. Your exact local rate may differ.
Sources
Frequently asked questions
How do you calculate sales tax on a purchase?
Multiply the pre-tax price by the sales tax rate expressed as a decimal. A $150 item at 8% tax: $150 × 0.08 = $12 in tax, for a total of $162. The calculator does this instantly — just enter the price and rate.
How do I back out sales tax from a total I already paid?
Divide the tax-inclusive total by (1 + rate as a decimal). If you paid $162 and the rate is 8%, the pre-tax price is $162 ÷ 1.08 = $150. Use the "remove tax from total" mode in the calculator for this.
What sales tax rate should I use?
Use your combined rate — the state rate plus any county and city rates that apply to your location. In the US, combined rates range from 0% in states with no sales tax to over 10% in some high-tax localities. Look up the rate for your specific address on your state's department of revenue website for the most accurate figure.
Which states have no sales tax?
As of recent data, five states — Alaska, Delaware, Montana, New Hampshire, and Oregon — have no statewide sales tax. Alaska allows local jurisdictions to levy their own sales taxes, so some Alaskan municipalities still charge tax. The others have no state or local sales tax.
Are groceries and prescriptions taxable?
It depends on the state. Many states exempt unprepared groceries and prescription drugs from sales tax, but policies differ widely. Some states tax groceries at a reduced rate, others exempt them entirely, and a few tax them at the full rate. Prepared food (restaurant meals, hot takeout) is almost always taxable.
When would I need to remove tax from a total?
Common situations include splitting an expense report between taxable and non-taxable portions, finding the pre-tax price on a receipt where tax is embedded in the total, or working backwards from a quoted all-in price to understand the true item cost. The reverse calculation is also useful for retailers reconciling sales receipts.
Is the combined rate the same everywhere in a state?
No. The statewide rate is a floor, but counties and cities can add their own rates on top. Within the same state you might pay 6% in one city and 9.5% in another. Always check the rate for the specific location where the sale occurs, not just the state average.
Do online purchases require me to pay sales tax?
Generally yes. Following a 2018 Supreme Court ruling (South Dakota v. Wayfair), states can require out-of-state online retailers to collect sales tax if they meet certain sales thresholds into that state. Most major online retailers now collect the appropriate rate for your shipping address. However, purchases from very small online sellers may not always include sales tax, and you may technically owe use tax to your state on those purchases.