Plus tax calculator

There is no such thing as “plus tax”

People type the price and the words together — “$19.99 plus tax” — because at the moment of asking, the price is the only fact they have. The trouble is that the phrase describes something that does not exist as a single number. Sales tax in the United States is set by the state, and then again by the county, and then again by the city, and there is no federal sales tax underneath any of it to make the answers converge.

On $19.99, the state-level spread runs from $19.99 to $21.44 — $1.45 of difference on a twenty-dollar purchase, which is 7.3% of the price. Alaska and Montana sit at the bottom because neither charges a state sales tax at all. California sits at the top with 7.25%, the highest state rate in the country.

So when a calculator answers this question with one number and no state, it has made a choice on your behalf and not told you. That is the thing worth knowing before you trust the total: whose rate did it use?

The cent that every other calculator gets wrong

Multiply the price by the rate and you get a number with more decimal places than money has. 6% of $19.99 is $1.1994. Somebody has to decide what happens to that 94, and the states have decided it in writing — differently.

Maryland does not multiply at all. Its Comptroller publishes a chart, and the chart is the law: six cents on each exact dollar, plus a fixed number of cents for the part above it, in bands. On $1.17 the chart says the tax is $0.08; multiplying by 6% and rounding says $0.07. On $0.21 the chart says $0.02 and multiplying says $0.01.

That is not a rounding curiosity confined to small change. Across every price from one cent to $100.00 — 10,000 of them — the chart and the multiplication disagree 4,835 times, or 48% of the time. The calculator on this page uses the chart for Maryland, because the chart is what the till uses.

There is a twist worth stating plainly, because it cuts against the point: on prices ending in .99 the two methods agree. If you came here for “$19.99 plus tax”, Maryland's chart and the arithmetic land on the same cent. The disagreement lives in prices whose cents fall in the bands the chart draws — anything ending .01 to .08, .17 to .25, .34 to .41, and so on. Which is to say: the ordinary calculator is right about the price you searched for, and wrong about half the prices you will meet.

Florida is here for the opposite reason. For decades Florida was the bracket-chart state, and a great deal of what is published about it online still says so. The bracket system was repealed. Florida carries the computation to the third decimal place and rounds up to the next cent whenever that third decimal is greater than four. The bracket system Florida was known for was repealed. The source is the statute itself, Fla. Stat. § 212.12(10), read 2026-09-16.

For the other 45 states this page computes the tax and rounds it to the nearest cent, rounding a half-cent up. That is what the states that publish a rule require, and it matches what tills do. It is also a place where this site has not read every state's own rounding provision, and says so rather than implying otherwise: if a state publishes a chart like Maryland's, the till could differ from this page by a cent.

What you are buying moves the answer more than the rate does

The rate is the part everyone looks up and the part that matters least. At $19.99, clothing carries no sales tax at all in 9 states — Alaska, Massachusetts, Minnesota, Montana, New Jersey, New York, Pennsylvania, Rhode Island and Vermont — so the same $19.99 that costs $21.44 on a shelf of electronics costs exactly $19.99 on a rail of shirts.

Groceries go further: at this amount, 37 of the 47 states charge nothing. And “groceries” is a category with edges that each state draws by hand. Sweets are the classic case — in many states a chocolate bar is not food, so it pays the full rate while the loaf of bread beside it pays nothing.

This is why the calculator asks what the thing is before it gives you a number. A tool that only asks for a price and a state is answering a narrower question than the one you have.

Why the price ends in .99, and what it does to the tax

Every one of the most-searched amounts ends in .99. That is charm pricing, and it is about how $20.00 reads next to $19.99 on a shelf — nothing to do with tax. The tax treats $19.99 as $19.99: there is no threshold at twenty dollars, no rounding down to the nearest dollar, no relief for stopping a cent short.

What the .99 does change is the last cent of the total, and it changes it in a predictable direction. A price ending in .99 produces a tax whose third decimal is high — 6% of $19.99 is $1.1994 — so it rounds up more often than a round price does. Over a weekly shop that is pennies. It is worth knowing only because it explains why the totals in the table above end where they do rather than on tidy numbers.

There is one real threshold effect, and it is not about the .99: it is about clothing. New York exempts clothing under $110.00 per item and taxes it at or above that, so a $109.99 coat and a $110.00 coat are taxed differently by one cent of price. That is the kind of cliff a price ending in .99 is genuinely designed around.

If you are the one ringing it up

A shopper wants one total. A seller has a different problem: a basket of twelve items, each of which produces a tax with three decimal places, and a choice about when to round.

Round each line and add them up, and you get one number. Add the taxable amounts first and round once at the end, and you can get another — they differ by a cent often enough to matter to anyone reconciling a day's takings. Florida's statute settles it explicitly, and settles it permissively: the rounding may be applied “to the aggregate tax amount computed on all taxable items on an invoice or to the taxable amount on each individual item”. Either is legal there; what is not legal is switching between them to suit the till.

This page rounds per item, because that is the question it was asked — one price, one total. If you are checking a multi-line receipt against it, add the lines the same way the shop did before deciding the shop got it wrong.

The other seller's trap is the one nobody warns about: the tax is owed whether or not you collected it. Quote a price “plus tax” and forget to add it, and the state's position is that the tax was inside the figure you charged — which is the reverse calculation, and it comes out of your margin.

The local rate is the part nobody can look up from a price

Everything above is the state layer. On top of it, most states let counties, cities and special districts add their own, and those are set by address rather than by state — two shops a mile apart can charge different totals for the same item, and a delivery is taxed where it arrives rather than where it was sold.

So the honest structure of the answer is: the state part is knowable from your state, and the local part is knowable only from your address. This page gives you the first exactly and takes the second as an input. Where a state forbids a local sales tax outright, the calculator ignores a local rate you type rather than charging a tax that does not exist; where the local rules have not been read in that state's own document, the page says the figure is a floor instead of pretending it is complete.

Ontario, and the rest of Canada

A good share of “plus tax” searches are Canadian — “$12.99 plus tax ontario”, and its cousin typed as raw arithmetic, “1800 × 1.13”. The 1.13 is Ontario's 13% HST, and multiplying by it is the right instinct, which is more than can be said for most of the American versions of this question.

Canada is simpler in the way that matters here: the rate is set federally and provincially, not by city, so a province really does have one answer. It is more complicated in another way — GST, HST, PST and QST are four different taxes with different bases, and in some provinces two of them stack. That is a different page: sales tax in every province, and the reverse calculation for a total that already includes it.

The states that are not here, and why

4 states have no figure on this page: Idaho, New Hampshire, Delaware and Oregon. Three of them are described everywhere as having no sales tax, and that is very probably right. It has not been read in a document those states publish, so it is not asserted here.

That distinction is the whole method. A calculator that quietly prints $19.99 for Delaware is making a claim it cannot support, and it will be right until the day it is not — a gross receipts tax passed through to the shelf price does not announce itself. Leaving a gap visible costs a page and keeps the rest of the figures worth something.

Where the figures come from

Every state rate on this page was read in a document published by the body that sets it, with the date recorded next to the figure. The two rounding rules — Comptroller of Maryland's Maryland Sales and Use Tax 6% Rate Chart (Rev. 06/18) and Fla. Stat. § 212.12(10) — were read on 2026-09-16 and 2026-09-16.

Nothing here is generated by a language model. The totals come from the same deterministic engine that produces the 47 state pages, and a model is used only to put a figure it has been handed into a sentence. The full method, and the log of every figure that turned out to be wrong in the compiled sources this category relies on, is on the methodology page.