How do I calculate sales tax backwards from a total?

Divide the total by 1 plus the rate to get the pre-tax price, then subtract that from the total to get the tax. With a $55.00 total at Los Angeles's 10.25%, $55.00 ÷ 1.1025 = $49.89 before tax, and the tax is $5.11. Check by multiplying $49.89 by 0.1025 and rounding to the cent.

How do I find the right sales tax rate for an address?

Use the state revenue department's address lookup, not a ZIP code table. ZIP codes cross city and district lines, so two customers in one ZIP can owe different rates. California, Texas, New York, Florida and most other states publish free rate lookups and downloadable rate files, and many update them every quarter.

Is shipping subject to sales tax?

It depends on the state. New York taxes shipping and handling when the item shipped is taxable. California exempts a separately stated delivery charge by common carrier or mail, up to your actual cost, but taxes handling and any markup. Many states sit between those two. Check your state's guidance before you set up checkout.

How do you round sales tax?

Most states round to the nearest cent, going up when the third decimal is 5 or more. States in the Streamlined Sales Tax Agreement let you round per item or once per invoice. A few states, such as Florida, use bracket tables. Since pennies stopped being made, some states let you round cash totals to the nearest nickel, but the tax itself is unchanged.

What is use tax and when do I owe it?

Use tax is the twin of sales tax. You owe it when you buy taxable goods without paying sales tax and use them in a taxing state, for example equipment bought from an out-of-state seller that did not charge tax. The rate equals the sales tax rate where you use the item, and businesses usually report it on their sales tax return.

Sales tax

How to Calculate Sales Tax in 2026: Formula, Combined Rates and Worked Examples

How to calculate sales tax in 2026: the formula, combined state and local rates, working back from a total, rounding, shipping and use tax, with US examples.

Edited by Sumeet YadavFounder & editor, MSMETOOLS · fact-checked against official sources

Updated October 2026 Verified against official sources 9 October 2026 20 min read

How to calculate sales tax — MSMETOOLS guide cover

Contents (11)

1. The sales tax formula
2. How state and local rates add up to a combined rate
3. Origin vs destination sourcing: whose rate do you charge?
4. Worked examples: adding sales tax to a price
5. How to calculate sales tax backwards from a total
6. Rounding rules, and what changed for cash in 2026
7. Is shipping taxable? Two states, two answers
8. Use tax: the other half of the calculation
9. Common mistakes and how to fix them
10. Where to register and how the money flows
11. What to do next

Every US business that sells taxable goods has to get one sum right thousands of times a year: the sales tax on each sale. The arithmetic is easy. The hard part is choosing the right rate, deciding what is taxable, and rounding the way your state expects. This guide is for shop owners, online sellers and bookkeepers. It covers the formula, how state and local rates combine, origin versus destination sourcing, working back from a tax-inclusive total, rounding (including the new nickel rules for cash), shipping and use tax. Every example uses real 2026 rates, checked against state revenue departments in October 2026.

Quick answer

Sales tax = taxable price × combined rate. Add the state rate and every local rate that applies, turn the total into a decimal (8.25% = 0.0825) and multiply. To work back from a tax-inclusive total, divide the total by (1 + rate). Round to the nearest cent unless your state uses brackets.

Houston example: $80 × 8.25% = $6.60 tax, $86.60 total
Most states charge the rate where the buyer receives the goods; Texas and partly California use the seller's location for in-state sales
Shipping is taxable in some states (New York) and exempt in others when separately stated (California)
If a seller doesn't charge you tax on a taxable purchase, you usually owe use tax at the same rate
Cash nickel rounding, allowed in some states since the penny stopped being made, does not change the tax you owe

The sales tax formula

The formula has three parts: the taxable price, the rate, and the tax. Multiply the first two and you get the third.

Sales tax = taxable price × combined sales tax rate

Total = taxable price + sales tax, or in one step, total = taxable price × (1 + rate)

To use a percentage in the formula, divide it by 100. A rate of 8.875% becomes 0.08875, and 6% becomes 0.06. A common mistake is multiplying by 8.875 instead of 0.08875, which gives an answer a hundred times too big. Another is leaving out the local part of the rate.

Take a $250 lamp sold to a customer in New York City, where the combined rate is 8.875%. The tax is $250 × 0.08875 = $22.1875, which rounds to $22.19. The customer pays $272.19. Even in this simple case you made two choices: you treated the whole $250 as taxable, and you rounded to the nearest cent. In real transactions, both depend on state rules.

"Taxable price" means the sales price after any discount you give, before tax. If you run a 20% off sale, tax the discounted price. In most states a store coupon you fund yourself also lowers the taxable amount. A manufacturer's coupon that someone else repays you for often does not, because you still collect the full price, partly from a third party. State rules on coupons and rebates differ, so read your state's guidance before you program the point of sale.

How state and local rates add up to a combined rate

Forty-five states and the District of Columbia charge a statewide sales tax. On top of it, most states let counties, cities, transit authorities and special districts add their own rates. The rate you charge is the combined rate: state plus every local layer that applies at that address.

Texas shows how the layers work. The state rate is 6.25%. Cities, counties, transit authorities and special purpose districts can add local taxes, but together they are capped at 2%. So no Texas address can exceed 8.25%, and most big cities sit at that cap. New York City is built differently. It combines the 4% state rate, the 4.5% city rate and the 0.375% Metropolitan Commuter Transportation District surcharge, for 8.875% in total. California starts with a 7.25% statewide base and adds district taxes of 0.10% to 2.00% each, which is how the City of Los Angeles reached 10.25%.

Place	State rate	Local layers	Combined rate
Houston, TX	6.25%	City, transit (capped at 2%)	8.25%
New York City, NY	4%	City 4.5% + MCTD 0.375%	8.875%
Los Angeles, CA	7.25%	District taxes	10.25%
Miami-Dade County, FL	6%	County surtax	7%
Washington State	6.5%	City/county, varies by location	Use the WA DOR lookup

Don't look up rates by ZIP code. ZIP codes are mail routes, not tax boundaries. One ZIP code can span two cities, an unincorporated county area and a special district, each with a different rate. State revenue departments publish address-based lookups and downloadable rate files for this reason, and many states change local rates every quarter, usually on January 1, April 1, July 1 or October 1. If you sell from one location, check the rate before each quarter starts. If you ship statewide, use the state's rate file or sales tax software that geocodes the delivery address.

Five states have no statewide sales tax: Alaska, Delaware, Montana, New Hampshire and Oregon. Alaska still lets boroughs and cities levy local sales taxes, so "no state tax" does not always mean "no tax". Use the sales tax calculator to see how a state rate and a local rate combine for any price.

Close-up of brass and enamel keys on a vintage cash register, including a Receipt key — A register only adds the right tax if it holds the right combined rate. Check local rates every quarter.· Image: Steve Snodgrass (CC BY 2.0)

Origin vs destination sourcing: whose rate do you charge?

When the customer walks out of your shop with the item, you charge your shop's rate. When you deliver or ship, it gets harder, because the state's sourcing rule decides whether the seller's location or the buyer's location sets the local rate.

Destination sourcing is the majority rule. You charge the combined rate of the address where the buyer receives the goods. New York works this way: a Rochester online seller shipping a taxable item to Manhattan charges 8.875%, not Monroe County's 8%. Florida does the same with its county surtax, so a Miami seller shipping to a county with no surtax charges only the 6% state rate. The 24 states that have adopted the Streamlined Sales and Use Tax Agreement use uniform sourcing rules, which generally point to the place the buyer receives the product.

Origin sourcing means the local rate follows the seller's place of business. Texas is the main example for in-state sales. A Texas retailer with a place of business in the state generally collects local tax based on that location, so an Austin shop shipping a taxable order to a small town elsewhere in Texas still applies its own local rate. Texas has defended this approach in rulemaking and in court in recent years. Sellers with unusual setups, such as several warehouses or orders taken in one city and filled in another, should read the Comptroller's local sales tax publications.

Remote sellers into Texas, meaning businesses with no Texas place of business that cross the $500,000 threshold, follow a different rule. They collect state tax plus local use tax based on where the order is delivered. They can also elect the single local use tax rate of 1.75%, applied to every Texas delivery, so they don't have to track hundreds of local rates.

California is a hybrid. The 7.25% base, including its 1% city and county share, follows the seller's location. Voter-approved district taxes follow the delivery address, but only if the seller is engaged in business in that district or is large enough to be treated that way. Our California sales tax guide has a worked example.

If you are not sure which rule applies, look at your state revenue department's guidance on "sourcing" or "local tax for deliveries". Charging your own rate on every shipped order is a common audit finding in destination states, and charging the customer's rate in an origin state can mean you over-collect. Money you over-collect belongs to the state or the customer, never to you.

Worked examples: adding sales tax to a price

The examples below show the calculation from the price to the final amount, with rounding at the end. Rates come from the state revenue departments' 2026 tables.

Example 1 — a counter sale in Houston. A hardware store sells a $80.00 drill. Houston's combined rate is 8.25%. The tax is $80.00 × 0.0825 = $6.60, and the customer pays $86.60. Nothing needs rounding.

Example 2 — a discounted order in New York City. A Brooklyn boutique sells a $140 jacket with a 15% store discount. The taxable price is $140 × 0.85 = $119.00, and the tax is $119.00 × 0.08875 = $10.56125, which rounds to $10.56. The total is $129.56. Watch the clothing rule: New York exempts clothing and footwear priced under $110 per item from the state 4%, and New York City from the city tax as well. This jacket is above the limit, so it is fully taxable.

Try it — sales tax on a $250 sale in New York City

Purchase AmountState

Local / County Rate

Purchase Amount$250.00

State Tax (4%)$10.00

Local Tax (4.875%)$12.19

Combined Rate8.88%

Total Amount (Including Tax)$272.19

Open the full Sales Tax Calculator (PDF, save, compare)

Example 3 — mixed taxable and exempt items. A Miami-Dade convenience store rings up $12.00 of grocery staples, which Florida exempts, and an $8.00 phone charger. Only the charger is taxable, at 7%: $8.00 × 0.07 = $0.56. The receipt total is $20.56. Taxing the groceries by mistake would over-collect 84 cents, and you'd owe that to the customer or the state.

Example 4 — a multi-item invoice with per-line tax. A café supplier invoices a Los Angeles coffee shop for three taxable items at 10.25%: $45.00, $18.50 and $6.25, a $69.75 subtotal. Taxed on the invoice total, that is $69.75 × 0.1025 = $7.1494, or $7.15. Taxed line by line, it is $4.61 + $1.90 + $0.64 = $7.15. Here the two methods agree. Sometimes they differ by a cent, which is why the next section matters.

How to calculate sales tax backwards from a total

Restaurants, market stalls, event vendors and some online sellers advertise tax-inclusive prices. At filing time you need to split each receipt into price and tax, because you report taxable sales and tax collected separately. You may also need to work backwards when a supplier gives you a total but no tax breakdown, or when you check whether a receipt was charged at the right rate.

Pre-tax price = total ÷ (1 + rate)

Tax included = total − pre-tax price

Suppose a Los Angeles food truck charges $55.00 including tax at 10.25%. The pre-tax price is $55.00 ÷ 1.1025 = $49.8866, which rounds to $49.89. The tax inside the total is $55.00 − $49.89 = $5.11. Check your result: $49.89 × 0.1025 = $5.1137, which rounds to $5.11, and $49.89 + $5.11 = $55.00. If the check is off by a cent, adjust the pre-tax figure by a cent and test again.

Don't take the rate as a share of the total. Multiplying $55.00 by 10.25% gives $5.64, which overstates the tax by 53 cents, because the total already includes the tax. That mistake inflates the tax you report and shrinks the revenue in your books.

Some states set conditions on tax-inclusive pricing. A few require you to tell customers the price includes tax, through signs or menu notes. Others limit tax-included pricing to particular businesses, such as vending machine operators or sellers at fairs. If you plan to sell this way, find your state's "tax included" guidance and keep a record of how you show it to customers.

Reverse sales tax in four steps

1
Find the combined rate for the sale location
Use the state's address lookup. For Los Angeles that is 10.25%, or 0.1025 as a decimal.
2
Divide the total by 1 + rate
$55.00 ÷ 1.1025 = $49.8866, rounded to $49.89.
3
Subtract to get the tax
$55.00 − $49.89 = $5.11.
4
Check by going forward
$49.89 × 0.1025 = $5.11 after rounding. If it doesn't match the total, move the pre-tax amount by one cent and retest.
Tip: Use the same rounding method your POS uses, or your return won't tie to your receipts.

Rounding rules, and what changed for cash in 2026

Once you multiply, you rarely land on a whole cent. Most states tell you to carry the result to three decimal places and round to the nearest cent, rounding up when the third decimal is 5 or higher. The Streamlined Sales Tax Governing Board's April 1, 2026 guidance states this rule, and member states such as Rhode Island have written it into law. Those states also let sellers round on an item basis (each line) or an invoice basis (once on the total), and they cannot force sellers to use bracket tables.

The two methods can differ. Ring up three $0.99 items at 8.875%. Per item, the tax is $0.0879, which rounds to $0.09, so $0.27 in total. On the invoice, it is $2.97 × 0.08875 = $0.2636, which rounds to $0.26. One cent doesn't matter on one receipt, but across a high-volume store it adds up over a year, and your return has to match how you actually collected. Pick one method, set it up in your POS, and use it every time.

Some states still use bracket systems, which publish tables of tax per price band. Florida is the best-known example, so a Florida retailer should load the state's bracket table into its register instead of assuming plain rounding. Our Florida sales tax guide explains how the brackets work.

The penny phase-out. The US Mint stopped making pennies in 2025, and some stores cannot give exact change in cash. The Streamlined Sales Tax board's guidance is clear: rounding a cash total to the nearest nickel does not change the sales tax calculation. Vermont's Act 128 of 2026 lets businesses round final cash totals to the nearest nickel. Totals ending in 1, 2, 6 or 7 cents round down and those ending in 3, 4, 8 or 9 round up, and the full tax is still remitted. In Vermont's own example, a $3.27 item with $0.29 tax totals $3.56, a cash customer may pay $3.55, and the business still reports $0.29. Several other states have passed or proposed similar rules. If you take cash, check your state's guidance and make sure the POS rounds the cash total, not the tax line.

Hands taping a cardboard parcel next to a laptop open on a shipping booking page — Shipping charges are taxable in some states and exempt in others. Set the rule up in checkout per state.· Image: Meanwell Packaging (CC BY 2.0)

Is shipping taxable? Two states, two answers

No federal rule covers sales tax on delivery charges. Each state decides, and the answers differ more than most sellers expect. California and New York show the range.

New York treats shipping and handling as part of the sale of a taxable item. If the goods are taxable, the delivery charge is taxable too, whether or not you list it separately. If the goods are exempt, or sold for resale, the delivery charge is not taxed. Mixed orders have a trap. If one delivery charge covers both taxable and exempt items, the whole charge is taxable unless you allocate it fairly between them. If the customer hires and pays a carrier directly, that charge is not part of your sale.

California goes the other way for most online sellers. A delivery charge is not taxable when the goods ship directly to the buyer by common carrier, contract carrier or US Mail, the charge appears as its own line, and it does not exceed your actual cost. Handling fees are taxable. If you charge more than the carrier charges you, the excess is taxable, and you cannot average costs across a quarter. Delivery in your own trucks follows separate rules. CDTFA Publication 100 has the full table.

Same order: $200 taxable goods + $15 shipping (actual cost $12)	New York City	Sacramento, CA
Combined rate	8.875%	8.75%
Taxable amount	$215.00 (goods + all shipping)	$203.00 (goods + $3 markup)
Sales tax	$19.08	$17.76
Customer pays	$234.08	$232.76

Most other states fall somewhere between these two. Many follow the Streamlined definition, which includes delivery charges in the sales price but lets states exempt them. Before you launch nationwide shipping, list the states where you collect tax and record each one's shipping rule in your checkout settings. "Free shipping" built into the item price is simply part of the taxable price.

Use tax: the other half of the calculation

Sales tax is charged by the seller. Use tax is paid by the buyer when no sales tax was charged on a taxable purchase that is used, stored or consumed in a taxing state. It uses the same calculation and the same combined rate as sales tax at the place of use. It exists so that buying from a seller that doesn't collect tax doesn't beat buying locally.

Since the Supreme Court's South Dakota v. Wayfair decision in June 2018, large online sellers have collected tax in most states once they pass economic nexus thresholds, such as $500,000 in California and Texas, $100,000 in Florida, and $500,000 plus more than 100 sales in New York. Smaller out-of-state vendors, auction sites, foreign suppliers and business-to-business sellers often still charge nothing. That is when your business owes use tax.

Remote seller thresholds in four big states (2026)

$500,000

California sales in the year

then register and collect

$500,000

Texas revenue, prior 12 months

or elect the 1.75% local rate

$500,000

New York sales

and more than 100 sales

$100,000

Florida taxable remote sales

prior calendar year

Example. A Dallas design studio buys a $3,000 workstation from a small out-of-state reseller that charges no tax. The studio uses it in Dallas, where the combined rate is 8.25%. It owes $3,000 × 0.0825 = $247.50 in use tax, reported on its Texas sales and use tax return for the period. If the seller had charged a lower rate from another state, most states give credit for tax already paid and you owe only the difference.

Inventory you buy to resell is not subject to use tax, because you give the supplier a resale certificate and the tax is collected later from your customer. If you take an item out of inventory for your own use, for example a furniture store using a display sofa in its office, you owe use tax on your cost. Auditors usually start with fixed-asset purchases, office supplies and software subscriptions bought online, so review those vendors each quarter.

Common mistakes and how to fix them

Most sales tax errors on audit come from the same few problems. Fix them before they turn into several years of assessments.

The first mistake is using a single statewide rate for everything. Unless you sell only from one shop in one district, set up rate lookups by address. If you have been undercharging, you still owe the full tax. Most states let you register late or come forward through a voluntary disclosure program, which usually limits the lookback and waives some penalties.

The second is calculating tax on the total, including the tax. If your reverse calculations or reports multiply a tax-inclusive total by the rate, you overstate the tax. Use the division method and test it against a few receipts.

The third is ignoring exemption certificates. A sale to a reseller or an exempt nonprofit is tax-free only if you keep a valid certificate on file. Without one, the auditor treats the sale as taxable and you owe the tax yourself. Collect the certificate before the first invoice and renew it on the state's schedule.

The fourth is treating shipping the same in every state. One national checkout setting will be wrong somewhere. The fifth is skipping use tax on your own purchases, which auditors check by matching vendor invoices against your returns.

Last, keep your records. Most states can audit three or four years back, and longer if you never filed. Keep invoices, exemption certificates, rate tables you used, and Z-reports from your registers. Clean records turn an audit into a few days' work instead of months.

Before your next sale

0/9

Where to register and how the money flows

You can only charge sales tax if you hold a sales tax permit (called a seller's permit, sales tax license or certificate of authority, depending on the state) in that state. Collecting tax without one is illegal in most states, and so is failing to collect after you should have registered. In most states registration is free and online. Our guides cover the Texas sales tax permit and the rules in California, New York, Florida and Virginia step by step.

The tax you collect is not your money. You hold it in trust and send it to the state on the return due date, which may be monthly, quarterly or annually depending on your sales volume. Some states give a small discount for filing on time, and most charge penalties and interest for late filing. Many businesses keep collected tax in a separate bank account so it isn't spent on operating costs before the return is due.

Your invoices need to show the tax as a separate line in most states, along with your business name and, in some states, your permit number. Our invoice generator lets you add a sales tax line at any rate. For more on what to include, see how to make an invoice.

Official sales tax links

What to do next

Write down every place you sell from or deliver to, look up each combined rate by address, and note each state's sourcing and shipping rule. Then test your POS or checkout with three sample orders: a counter sale, a shipped order and a tax-inclusive total worked backwards. If the numbers match the examples above, your setup is sound. Use the sales tax calculator for quick checks and the discount calculator to confirm the taxable price after a promotion.

This is general information, not legal or tax advice — confirm on the official source or with a professional.

Frequently asked questions

Multiply the taxable price by the combined rate written as a decimal: sales tax = taxable price × rate. A $80 item in Houston, where the combined rate is 8.25%, carries $80 × 0.0825 = $6.60 of tax, so the customer pays $86.60. The combined rate is the state rate plus every local rate that applies at the place of sale or delivery.

Sources & verification

Figures on this page were checked against the sources below when it was last reviewed on 9 October 2026. Each rate and limit is stored once with its own official source and review date, and official update channels are monitored daily so changes are picked up. How we verify

1.Sales and Use Tax — Texas Comptroller of Public Accounts · accessed 9 October 2026
2.Remote Sellers — Texas Comptroller of Public Accounts · accessed 9 October 2026
3.Shipping and Delivery Charges (Publication 100) — California Department of Tax and Fee Administration · accessed 9 October 2026
4.Shipping and delivery charges (Tax Bulletin ST-838) — New York State Department of Taxation and Finance · accessed 9 October 2026
5.Penny Elimination — Streamlined Sales Tax Governing Board · accessed 9 October 2026
6.About the Streamlined Sales Tax Governing Board — Streamlined Sales Tax Governing Board · accessed 9 October 2026
7.Guidance for retailers and consumers on the phase-out of the penny in cash transactions — Vermont Department of Taxes · accessed 9 October 2026
8.R.I. Gen. Laws § 44-18.1-25 (Streamlined rounding rule) — Rhode Island General Assembly · accessed 9 October 2026
9.California City & County Sales & Use Tax Rates — California Department of Tax and Fee Administration · accessed 9 October 2026

MSMETOOLS is an independent platform and is not affiliated with any government agency, ministry or department.

We provide tools, guides and information for general educational purposes only. Always refer to official government websites for the latest and most accurate information.