Sales Tax Calculator
Add sales tax to a price, or reverse it out of a receipt total. Combine state and local rates and see the pre-tax amount, tax, and total.
- Free, no account
- No watermark
- No usage limit
About the Sales Tax Calculator
Backing tax out of a total is the one piece of sales tax math almost everyone fumbles. People take the tax percentage off the receipt total and call that the pre-tax price, but that answer always comes out too high. Reverse mode here does it the right way, and doing that job is the reason this page exists.
The everyday half is simpler. In Add mode you type a price and a rate and get the tax plus the total, so $100 at 8.25% is $8.25 in tax and $108.25 to pay. Flip to Reverse, hand it that $108.25 total and the same rate, and it gives back the $100 item and the $8.25 of tax buried inside it. You can split the rate into a state part and a local part so the number matches what a real register rings up, and everything runs in your browser with nothing uploaded.
How to use
- Pick a mode. Add tax if you have the price and want the total. Reverse (from total) if you already paid and want the pre-tax amount hiding inside the total.
- Enter the amount. Add mode wants the shelf price before tax. Reverse mode wants the full amount you paid, tax included.
- Enter the rate. Type the sales tax percentage for wherever the sale happened. One box is enough for a plain state rate.
- Split state and local if you need it. Tick "Split the rate into state + local" and a second field appears. The tool adds the two, say 6.25 state and 2 city, and applies the 8.25 combined.
- Read the result. You get the combined rate it used, the amount, the tax on its own line, and the total (or the pre-tax figure). Change any field and it all recomputes on the spot.
Leave the amount blank and you get a dash with a short prompt instead of an error. Type a negative rate and it's read as zero, because there's no such thing as negative sales tax.
The reverse calculation people get wrong
Say your receipt total is $108.25 and the rate was 8.25%. The wrong move, the one most people reach for on instinct, is to take 8.25% of $108.25 (that's $8.93) and subtract it, landing on $99.32 as the "pre-tax" price, which is off by 68 cents. It's wrong because the 8.25% was never charged on $108.25 in the first place. It was charged on the smaller pre-tax number, so peeling the percentage off the bigger number over-counts every single time.
The right move is a division. Take the total and divide it by 1 plus the rate written as a decimal. $108.25 divided by 1.0825 comes out to exactly $100.00, and the tax is the $8.25 left over. That's the formula the tool runs, pre-tax = total / (1 + rate), and it's the whole trick to reading tax out of any receipt.
Sixty-eight cents is nothing on a coffee. On a $4,000 conference invoice it starts to count, and on a resale filing where you back tax out of forty line items the same mistake rides along on every row. Use the wrong method once and every row on the sheet is off by the same amount. Reverse mode does the division for you and never guesses which way it goes.
The state rate almost never matches your receipt
The rate on a real receipt is usually a stack. State on the bottom, then county, then city, and sometimes a special district tacked on for a transit line or a stadium. They pile on top of one another.
Texas is the easy example. The statewide rate is 6.25%, but local add-ons can push it to 8.25%, which is the number you see across most of the state. California starts at 7.25% and clears 10% in some cities once the local pieces land. So plug in only the state figure and your total comes out low, sometimes by a lot.
That's the reason the split checkbox is here. Put the state rate in one box and your local rate in the other and the tool sums them into the number that actually matches the register. For anything that has to be exact, an invoice, an expense claim, a resale record, use the rate for the precise place the sale happened. For a shipped order that's usually the delivery address not the store's. A generic state preset is fine for a rough guess, though anything official needs the exact local rate.
Frequently asked questions
Which rate applies to an online order, mine or the seller's?
Usually yours. Most states set the rate by where the buyer takes delivery, so an online order is taxed on your shipping address. Since the 2018 Wayfair court ruling, out-of-state sellers have to collect it once they cross a state's sales threshold, which is why the tax on your cart reflects your ZIP now instead of the warehouse's. Enter the delivery-address rate here, not the seller's.
Is tax charged before or after a discount?
After, in almost every case. Tax applies to what you actually hand over, so a coupon or a markdown shrinks the taxable amount too. A $50 shirt at 20 percent off is taxed on the $40 you pay, not the $50 on the sticker. Manufacturer rebates can behave differently in a handful of states, but for a normal store discount, work out the sale price first and run that number through the tool.
The five no-sales-tax states, do they really charge nothing?
At the state level, yes. Alaska, Delaware, Montana, New Hampshire and Oregon have no statewide sales tax. But no state tax doesn't always mean no tax at all. Alaska lets towns levy their own local rate, so plenty of Alaskan purchases still carry one while the next town over is genuinely free. Enter 0 only when the specific locality has nothing either. Otherwise put in whatever local rate applies.
Why doesn't my total match my friend's on the same item?
Different rates, and sometimes different rules. Sales tax is set by state, county, city and the occasional special district, so two people a few miles apart can pay different totals on an identical item. What counts as taxable shifts around as well. Groceries, clothing and prescriptions are exempt or reduced in a lot of places and fully taxed in others. Use the rate and item that match your own location and the total lines up.
How many decimals does it handle?
Rates go in with full decimals, so 8.375% or 4.45% enter exactly as written with no rounding on your end. Money lands on a whole cent as each line is worked out rather than only when it is printed, which is why the three rows add up to each other and why an exact half cent rounds up the way a register does it. A receipt can still come out a penny different, and the usual reason is that the shop taxes each item on its own and then adds those up, where this taxes the whole basket at once.
Does anything I type get sent anywhere?
No. Every calculation happens on your device inside the browser. Amounts, rates and totals aren't uploaded, logged, or checked against any server, and there are no live rate feeds contacting anything. It also keeps working with no connection once the page has loaded, which is handy when you're standing in a store checking a price on one bar of signal.