Sales Tax Calculator

Sales tax is price × rate, and the total is price + tax. That is the whole of the arithmetic. The part that actually costs people money is the rate, because in the US it is not one number. It is a stack of state, county, city and special-district pieces that only resolves once you know the exact delivery address.

This guide covers the arithmetic in both directions, including working backwards from a tax-inclusive total to the pre-tax price, how the combined state and local rate is built, where to get your own rate without guessing, what is and is not taxable, when selling into a state forces you to register there, and why marketplace sellers on Amazon, eBay and Etsy have far less to do than they think.

The Sales Tax Calculator takes two inputs, a pre-tax amount and a rate, and returns the tax and the total. Everything below is built on those two inputs.

How to calculate sales tax on any price

There are only two operations:

Sales tax = price × (rate ÷ 100) Total = price + sales tax

The table below uses 8.25% as a worked example rate. It is not a real jurisdiction's rate, it is just a round-ish number in the middle of the range most US shoppers see, so you can follow the arithmetic. Substitute your own combined rate and the shape of the answer is identical.

Pre-tax price	Sales tax at 8.25%	Total to pay
$9.99	$0.82	$10.81
$19.99	$1.65	$21.64
$25.00	$2.06	$27.06
$49.99	$4.12	$54.11
$100.00	$8.25	$108.25
$250.00	$20.63	$270.63
$500.00	$41.25	$541.25
$1,000.00	$82.50	$1,082.50
$2,500.00	$206.25	$2,706.25
$5,000.00	$412.50	$5,412.50
$25,000.00	$2,062.50	$27,062.50

Two details are worth pausing on. The $250 row calculates to $20.625 and lands at $20.63, because tax is rounded to the nearest cent with half a cent going up. That is why your own arithmetic and a register receipt occasionally differ by a penny. And the tax scales perfectly linearly: unlike a payment processing fee, there is no fixed component, so the effective rate on a $9.99 item is identical to the rate on a $25,000 one.

The formula also makes obvious how much the rate matters on a big-ticket item. On a $1,250 sofa, each percentage point of combined rate is $12.50. A buyer in a 10% jurisdiction pays $125.00 in tax; a buyer in a 6% jurisdiction pays $75.00; a buyer in a state with no sales tax pays nothing. That $125 spread on a single item is why furniture and appliance retailers near state lines advertise the way they do.

How do you work out the price before tax?

This is the reverse calculation, and it is the one people get wrong. You have a tax-inclusive figure, a receipt total, a gross deposit, a price advertised "tax included", and you need the pre-tax price and the tax that is buried in it.

You cannot subtract the rate. You have to divide it out:

Pre-tax price = total ÷ (1 + rate ÷ 100) Tax included = total − pre-tax price

Worked through on a receipt total of $86.42 at a 6.5% combined rate:

• Convert the rate to a divisor: 1 + (6.5 ÷ 100) = 1.065
• Divide the total: $86.42 ÷ 1.065 = $81.1455, rounded to $81.15
• Subtract to get the tax: $86.42 − $81.15 = $5.27
• Check it forward: $81.15 × 6.5% = $5.27, and $81.15 + $5.27 = $86.42

That last step is the one that matters. A reverse calculation is only right if it round-trips.

Here is the same division across a range of totals and rates:

Tax-inclusive total	Rate	Pre-tax price	Tax included
$21.64	8.25%	$19.99	$1.65
$50.00	6.00%	$47.17	$2.83
$86.42	6.50%	$81.15	$5.27
$100.00	7.00%	$93.46	$6.54
$100.00	8.25%	$92.38	$7.62
$100.00	8.875%	$91.85	$8.15
$250.00	9.50%	$228.31	$21.69
$400.00	10.25%	$362.81	$37.19
$1,000.00	8.25%	$923.79	$76.21
$1,299.00	9.50%	$1,186.30	$112.70
$2,000.00	9.50%	$1,826.48	$173.52

Why subtracting the rate does not work. On a $108.25 receipt at 8.25%, taking 8.25% off the total gives $99.32, which is 68 cents adrift of the real $100.00 pre-tax price. The rate applies to the pre-tax base, not to the tax-inclusive figure, so the amount you are taking the percentage of is too big. The error grows with both the rate and the amount: on a $500 tax-inclusive total at 10.25%, the shortcut says $448.75 when the real pre-tax price is $453.51, a $4.76 miss. Across a few hundred transactions that is a reconciliation you will never balance.

How to use a reverse sales tax calculator

The calculator on this page runs forward, pre-tax amount plus rate gives you tax and total. To reverse it, do the division yourself and then use the calculator as the proof:

1. Divide your tax-inclusive total by (1 + rate ÷ 100) to get the pre-tax price.
2. Enter that pre-tax price and your rate into the Sales Tax Calculator.
3. If the total it returns matches the receipt you started with, your reverse figure is right. If it is a cent out, that is rounding, and it is normal.

The same division is how you gross a price up to hit a round shelf number. To land on exactly $100.00 including 8.25% tax, list the item at $92.38: the tax comes to $7.62 and the total is $100.00. To land on $50.00 at the same rate, list at $46.19, tax $3.81. Retailers who advertise "tax included" pricing are doing this on every line of the catalogue, and it is worth checking, because a gross-up error eats margin silently rather than showing up as an unpaid bill.

If it is percentage arithmetic in general that is tripping you up rather than sales tax specifically, the Percentage Calculator handles adding, removing and reversing any percentage. And if you are outside the US, note that VAT is normally quoted tax-inclusive already, so this reverse calculation is the default rather than the exception. The VAT Calculator is the right tool there.

How does a sales tax calculator handle state and local rates?

It does not, and no honest one can, unless it is looking up a live rate table by street address. What a calculator does is apply the rate you give it. Getting that rate right is your job, and it is the part worth understanding.

The rate a buyer pays is a sum, not a single figure. Four layers can apply to the same purchase:

Layer	Who sets it	Notes
State	The state legislature	The only layer that is the same everywhere in the state
County or parish	County government	Not every county levies one
City or municipality	City government	Often the largest local layer in big cities
Special district	Transit authorities, improvement districts, stadium and hospital districts	Boundaries frequently do not follow city lines

Add them together and you get the combined rate, which is the single number on the receipt and the single number you type into the calculator. In many states the local layers together are larger than the state layer, which is the opposite of how most people assume sales tax works. A low state rate tells you almost nothing about what a shopper actually pays.

Where to get your combined rate. Take it from the source, not from a blog post, because rates change on a rolling basis and usually on the first day of a quarter:

• Your state department of revenue or equivalent, which publishes an official rate lookup and downloadable rate tables. This is the authoritative answer and it is free.
• Your point of sale or e-commerce platform, if it does address-level rate determination at checkout. Verify it against the state lookup once when you set it up.
• A paid tax automation service, if you are filing in enough states that maintaining rates by hand has become a job.

Do not look rates up by ZIP code. ZIP codes were designed for mail routing and regularly straddle city and district boundaries, so one ZIP can contain two or three different combined rates. Rate determination should use the full street address, and an audit will use the street address too.

Origin-based vs destination-based sourcing: which rate do you charge?

When a seller in one city ships to a buyer in another, one of two rules decides whose rate applies.

Destination-based sourcing, used by the large majority of states, means you charge the rate at the buyer's delivery address. If you ship to a customer in another city, you charge that city's combined rate, not yours.

Origin-based sourcing means you charge the rate at your own location. A shop selling to a customer elsewhere in the same state charges its own combined rate regardless of where the parcel goes.

Two things make this less confusing than it sounds. First, origin sourcing generally applies only within a state. Sales that cross state lines are almost always destination-sourced. Second, a few states are hybrids, applying origin rules to the state and county portions while treating district taxes as destination-based, which is why rate determination in those states is notoriously fiddly and why sellers there lean hardest on automation.

The practical consequence for a small seller is that a single "my rate" figure does not exist once you ship outside your own city. If you ship nationally you are quoting dozens of different rates, which is why automated rate lookup at checkout stopped being optional years ago.

California sales tax: how the rate on your receipt is built

California's combined rate is a statewide base rate plus district taxes approved by local voters. The base applies everywhere in the state. The district taxes do not: they are levied by cities, counties and special districts, they are approved individually at the ballot box, and several can overlap on the same address. That is why two addresses a mile apart can carry different totals, and why the difference between neighbouring cities is usually district tax rather than anything the state did.

California also runs the hybrid sourcing described above. For an in-state sale, the state and county portion generally follows the seller's location while district tax generally follows where the goods are delivered or used. For a seller shipping across the state, that means the rate is assembled from two different places at once.

Where to get the number. The California Department of Tax and Fee Administration (CDTFA) publishes an official "find a sales and use tax rate by address" lookup and quarterly rate tables. Use the full street address, take the combined figure it returns, and enter that into the calculator. Do not use a rate you remember, and do not use a city-level rate for an address you have not checked, because district boundaries do not reliably follow city limits.

Two California specifics worth knowing as a shopper or seller. Unprepared food for home consumption and prescription medicine are broadly exempt, while prepared food and restaurant meals are not. And a district tax generally applies only to sales delivered into that district, so a seller with no presence there may still owe it on shipments in once nexus applies.

Missouri sales tax calculator: finding the right combined rate

Missouri is one of the clearest illustrations of why a state rate is useless on its own. On top of the statewide rate, counties, cities and a long list of special districts each levy their own. Missouri makes heavy use of transportation development districts and community improvement districts, small taxing areas that can cover a single shopping centre or even one side of a street. Two stores in the same retail park can sit in different districts and charge different totals.

Missouri also draws a distinction that catches out-of-state sellers: the local use tax rate that applies to a remote purchase is not automatically the same as the local sales tax rate that applies in a physical store, because not every jurisdiction has adopted a local use tax. In practice that means the rate you charge shipping into a Missouri address may differ from the rate on the shelf there.

Where to get the number. The Missouri Department of Revenue publishes sales and use tax rate tables and an address-based rate lookup, updated quarterly. Look the address up, note whether you need the sales tax or the use tax rate for the transaction you are doing, and enter the combined figure into the calculator.

One more thing worth correcting, because older guides still say it: Missouri was the last sales tax state to require out-of-state sellers to collect. Guidance written before that change said remote sellers had nothing to do in Missouri. That is no longer true, and a seller relying on it is accruing liability.

New Jersey sales tax: one statewide rate, a few exceptions

New Jersey is unusual in the opposite direction. It levies a single statewide rate with no general county or municipal sales tax on top, so for most purchases at most addresses there is one rate for the entire state. That makes New Jersey one of the few places where quoting a single figure is actually defensible, and it means a calculator is genuinely all you need once you have the current statewide rate from the source.

The exceptions are narrow but real:

• Urban Enterprise Zones. Qualified businesses in designated zones may charge a reduced rate, historically half the statewide rate, on certain in-person retail sales of tangible goods. It does not apply to everything and it does not apply to shipped orders.
• Salem County. A similar partial-rate arrangement applies to qualifying in-person retail sales in the county.
• Exempt categories. Most clothing and footwear for everyday use is exempt, as are unprepared groceries and prescription medicine. Prepared food, and specifically listed items such as fur clothing and some accessories, are taxable.

Where to get the number. The New Jersey Division of Taxation publishes the current rate and the terms of the reduced-rate programmes. Check it rather than reusing a rate from a previous year, because New Jersey has changed its statewide rate more than once in recent memory.

The five states with no statewide sales tax

Five states levy no general statewide sales tax, remembered by the acronym NOMAD:

State	Statewide sales tax	Local sales tax?
New Hampshire	None	No
Oregon	None	No
Montana	None	Only local resort and lodging taxes in a few tourist towns
Alaska	None	Yes, many boroughs and cities levy their own
Delaware	None	No, but a gross receipts tax applies to sellers

Alaska is the one that misleads people. There is no state sales tax, but well over a hundred local jurisdictions levy their own, and Alaska municipalities have banded together into a single remote-seller programme, so a seller on the mainland can genuinely owe Alaska sales tax. Delaware's gross receipts tax is not a sales tax and is not charged to the customer. It is levied on the seller's revenue, so it quietly reduces margin instead of appearing at checkout.

These states generally recover the revenue elsewhere, through income tax or property tax, so "no sales tax" is not the same as a lower overall tax burden. If a move is on the table, compare the whole picture with the Take-Home Pay Calculator rather than the sales tax rate alone.

What is taxable and what is exempt

Exemptions are set state by state and there is no national pattern, but four categories come up constantly.

Groceries. Most states exempt unprepared food for home consumption entirely. Several tax it at a reduced rate, and a small number tax it at the full rate. Prepared food, restaurant meals, soft drinks and candy are usually taxable even where groceries are not, which is why a rotisserie chicken and a raw one can be taxed differently in the same store.

Prescription medicine. Exempt in essentially every state that has a sales tax. Over-the-counter medicine is a separate question and is often taxable.

Clothing. The most inconsistent category of all. A few states exempt most clothing outright. Some exempt it below a per-garment price threshold, and at least one taxes only the portion of a garment's price above a threshold. Most states tax clothing normally. If you sell apparel into multiple states, this is the category that will cost you the most in setup time.

Digital goods and software. The fastest-moving area. A large and growing share of states now tax at least some digital products, and many now tax software-as-a-service, which catches software businesses that assumed sales tax was a physical-goods problem. Because this is where legislatures are most active, it is also where guidance goes stale fastest.

Shipping deserves its own line. Many states treat delivery charges on a taxable sale as part of the taxable amount. On an $80 item with $12 shipping at 8.25%, tax on the item alone is $6.60, but tax on the full $92 is $7.59. Across a thousand orders that is $990 of tax you either failed to collect or paid out of your own pocket.

Resale certificates are the exemption every seller should be using. When you buy inventory you intend to resell, you should not pay sales tax on it, because the tax is meant to be charged once, at the final retail sale. You give the supplier a resale certificate, a state-issued form referencing your sales tax permit, and they sell to you tax-free. On $40,000 of inventory a year in a jurisdiction with an 8.25% combined rate, that certificate is worth $3,300 you would otherwise have paid and could not fully recover. Two cautions: certificates cover goods for resale only, not the office chairs and packing tape you consume yourself, and misusing one is a straightforward audit finding. If you import, note that sales tax is separate from duty and freight, which the Landed Cost Calculator covers.

Sales tax vs VAT: what actually differs

Outside the US, most countries use value-added tax instead. The difference is not the rate, it is where in the chain the tax is collected.

How it works	US sales tax	VAT
Collected at	The final retail sale only	Every stage of the supply chain
Shown in the price	Added at checkout	Usually included in the shelf price
Business purchases	Exempt via resale certificate	Paid, then reclaimed as input tax
Who sets it	Each state, county and city	National government
Rate variation within a country	Thousands of combined rates	Usually one standard rate plus reduced rates

Sales tax is a single-stage tax charged once, at the end. VAT is multi-stage: each business in the chain charges it on sales, reclaims it on purchases, and remits the difference, so the tax rides along the whole chain but only the final consumer bears the full amount.

The practical consequence for anyone arriving at this page from outside the US: a US price quoted online is usually exclusive of sales tax, so the checkout total will be higher than the price you saw. A European or UK price is usually inclusive of VAT, so the checkout total is the price you saw. The UK standard VAT rate is 20%, with reduced and zero rates for specific categories, which means the reverse calculation on this page is the one you want, not the forward one. Work those numbers with the VAT Calculator.

For US sellers shipping to the UK or EU, VAT is a real obligation with its own registration thresholds and import rules, and it is charged on top of duty on the customs value. If you are pricing for an international catalogue, how to price products for profit covers building tax into the number rather than discovering it afterwards.

Marketplace facilitator rules: why Amazon, eBay and Etsy already collect for you

This is the single most useful thing a marketplace seller can understand, and it saves an enormous amount of unnecessary work.

Every state with a sales tax has passed a marketplace facilitator law. These shift the duty to calculate, collect and remit sales tax from the individual seller to the platform. If your sales run through a marketplace, the marketplace is the party on the hook.

Sales channel	Who calculates and collects	Who files and remits	What you are still responsible for
Amazon (FBA and FBM)	Amazon	Amazon	Reporting gross sales where your state requires it
eBay	eBay	eBay	Same
Etsy	Etsy	Etsy	Same
Walmart Marketplace	Walmart	Walmart	Same
TikTok Shop	TikTok	TikTok	Same
Poshmark	Poshmark	Poshmark	Same
Your own Shopify store	You	You	Registration, collection, filing, everything
Your own site with Stripe or PayPal	You	You	Registration, collection, filing, everything

The line that catches people is the bottom half. Shopify is not a marketplace facilitator. It is software you use to run your own store, and you are the seller of record. Shopify will calculate the rate at checkout, but registering in each state, filing the returns and remitting the money are yours. The same is true of WooCommerce, BigCommerce, Squarespace and any site where you take payment through Stripe or PayPal.

Two follow-on points. Whether marketplace-facilitated sales count toward your own registration threshold varies by state, some include them and some exclude them, so a seller splitting volume between Etsy and a Shopify store may or may not have crossed a threshold in a given state. And in several states you must still report those gross marketplace sales on your return and then deduct them, so registration does not always mean zero paperwork.

If you sell across several channels, the Marketplace Fee Comparison Calculator shows the full cost of each one alongside its compliance load, and how much Amazon takes from a sale breaks down where the rest of the money goes.

When do you have to register in another state?

Before 2018, a state could only require you to collect sales tax if you had a physical presence there, an office, a warehouse, staff or inventory. South Dakota v. Wayfair overturned that. States can now require collection based purely on how much you sell into them, and every state with a sales tax has enacted an economic nexus threshold.

The common shape is a dollar threshold of sales into the state, sometimes paired with a transaction count, measured over the current or previous calendar year. The dollar figures and the transaction counts differ by state, several states have raised or removed the transaction prong since they first legislated, and a few use a materially higher dollar threshold than the rest. Because these have been amended repeatedly, take the current threshold from the state's own department of revenue rather than from any list, including this one.

Physical presence still creates nexus on its own, and it is easier to trigger than sellers expect. Storing inventory in a third-party warehouse counts. So does attending a trade show in some states, or having a remote contractor. For anyone using Amazon FBA, Amazon's own placement decisions can move your stock into states you have never visited.

Crossing a threshold does not tax you retroactively. It obliges you to register, then start collecting from a specified date forward. The real risk is not noticing you crossed it, because the liability accrues whether you collected or not, and if you did not collect, it comes out of your own margin. On $150,000 of sales into a state at a 7% combined rate, that is $10,500 you owe and never took from the customer. Run a shortfall like that through the Profit Margin Calculator once and the incentive to register on time becomes obvious.

Filing frequency, deadlines and what late filing costs

Once you register, the state assigns a filing frequency based on how much tax you collect. Higher volume means more frequent filing. The pattern is close to universal even though the cutoffs differ:

Amount of tax collected	Usual frequency	Return due
Small	Annual	Once a year
Moderate	Quarterly	The month after each quarter ends
Large	Monthly	Usually mid-month or the 20th of the following month
Very large	Monthly plus prepayments	A mid-month advance payment as well

Two rules trip up new registrants. You must file even when you collected nothing. A zero return is still a return, and missing it draws a penalty in most states. And the money was never yours: sales tax you collect is held in trust for the state, which is why failing to remit it is treated far more seriously than a late income tax payment, and why officers of a business can be held personally liable for it in many states.

Penalties are typically a percentage of the tax due per month, capped after a few months, plus interest that keeps running. The figures below are illustrative arithmetic, not any state's actual rates, using 5% per month capped at 25% with 8% annual interest on a $4,000 quarterly liability, to show the shape:

How late	Penalty rate	Penalty	Interest	Total added
1 month	5%	$200.00	$26.67	$226.67
2 months	10%	$400.00	$53.33	$453.33
3 months	15%	$600.00	$80.00	$680.00
6 months	25% (capped)	$1,000.00	$160.00	$1,160.00
12 months	25% (capped)	$1,000.00	$320.00	$1,320.00

Your state's actual penalty and interest rates are published on its department of revenue site, and some add a flat minimum penalty even on a zero return. The shape holds regardless: the penalty front-loads in the first few months, then interest accrues indefinitely. A number of states also offer a small vendor discount, a fraction of the tax collected, for filing on time, so punctual filing can be mildly profitable as well as cheaper.

Common mistakes

Subtracting the rate from a tax-inclusive total. Taking 8.25% off a $108.25 receipt gives $99.32, not $100.00. You have to divide by 1.0825. This is the single most common sales tax arithmetic mistake, and the error scales with both the rate and the amount.

Using the state rate instead of the combined rate. In most states the state rate is only part of what the customer pays. Quoting it as if it were the whole rate understates every order, and on a large one the gap is real money you either did not collect or did not budget for.

Reusing a rate you looked up last year. Local rates change on a rolling basis, usually at the start of a quarter, and a district can be created or expire without anything obvious happening at street level. Re-check the addresses you sell into most.

Assuming Shopify collects and remits like Amazon does. Marketplace facilitator laws cover marketplaces. Shopify is your store, you are the seller of record, and registration and filing are entirely yours. Sellers who move from eBay to their own Shopify store frequently inherit a compliance obligation they did not have before and do not notice for a year.

Looking rates up by ZIP code. ZIP codes cross taxing boundaries. One ZIP can contain two or three combined rates, and an audit uses the street address.

Forgetting that shipping is taxable in many states. Tax on an $80 item is $6.60 at 8.25%. Tax on the same item with $12 of shipping, where shipping is taxable, is $7.59. Small per order, large per year.

Treating collected tax as revenue. It sits in your bank account, so it inflates every dashboard you look at. It is not income, it is money held in trust, and spending it is the fastest way to turn a cash flow problem into a personal liability. Book it as a liability the day you collect it.

Related calculators

• VAT Calculator: the tax-inclusive equivalent used across the UK and EU
• Percentage Calculator: add, remove or reverse any percentage, tax or otherwise
• Profit Margin Calculator: see what uncollected tax does to a margin
• Marketplace Fee Comparison: platform fees alongside who handles tax on each channel
• Landed Cost Calculator: duty, freight and import taxes on goods you bring in
• Discount and Margin Calculator: price after a markdown, before tax is applied
• Amazon FBA Profit Calculator: full unit economics for a marketplace-facilitated channel