About ReverseTaxCalc
What This Is
Hi, I'm Mohibul Islam — an organic SEO specialist and the person who built ReverseTaxCalc. I started it because I kept running into the same problem. I'd be sitting there with a stack of receipts — usually at the worst possible time, like the night before expense reports were due — and I needed to know what I actually paid for each item before sales tax got tacked on. The total on the receipt was right there. The tax rate, I could look up. But doing that division backwards in my head? Not happening at 11 PM.
Expense reports were the first headache, but receipt reconciliation turned out to be just as annoying. You buy something for $53.49, you know your state charges 7.25%, and you need the pre-tax amount to match against a purchase order or budget line item. It sounds like a simple thing. It is a simple thing, mathematically. But when you're doing it for 30 receipts in a row, simple gets tedious fast.
So I built a calculator that does exactly one job: you put in the total you paid and the tax rate, and it tells you the original price and how much of your total was tax. That's it. No ten-step wizards, no "create an account to see your results." Just the answer.
Over time it grew a bit. People wanted state-specific versions with the rates pre-filled. Others needed to compare what they'd pay across state lines. The core idea hasn't changed though — it should take about five seconds to get your answer, and you shouldn't have to hand over your email address to do it.
Who Uses It
Bookkeepers are probably the most frequent visitors. They're reconciling receipts against invoices and need the pre-tax breakdown fast, especially when a client hands over a shoebox of gas station receipts with faded ink. Small business owners show up for a different reason — they're trying to figure out how much of their daily revenue is actually sales versus tax collected, which matters a lot when you're forecasting cash flow and you suddenly realize a chunk of your "income" belongs to the state. Then there are shoppers, the comparison crowd, who want to know whether buying a laptop in Oregon (no sales tax) actually saves enough over buying it in their home state to justify the trip or the shipping — turns out the answer depends a lot on what state you're in. And freelancers round it out, mostly during tax season, when they're pulling apart old expense reports and need to separate the deductible purchase price from the non-deductible sales tax they paid.
How I Keep the Rates Accurate
State-level sales tax rates on this site come from the Tax Foundation's annual publication on state and local tax rates. It's the most widely cited source for this data, and they update it each year around midyear. I pull the new figures as soon as they're published and verify them against each state's department of revenue.
Local rates are trickier. The "combined rate" you see for each state is a population-weighted average that blends state, county, and city taxes into one number. Your actual combined rate could be higher or lower depending on exactly where you are. A purchase in downtown Chicago carries a different local tax load than one in rural Champaign County, even though the Illinois state rate is the same. I flag this wherever it matters, and I always recommend verifying the specific combined rate for your city or county if you need precision — your state's tax authority website is the best place for that.
Rates do change, sometimes at awkward times. Louisiana dropped its state rate in January 2025, for example, which shifted the combined average for the whole state. When changes like that happen, I update as quickly as I can, usually within a few days. If you spot a rate that's out of date, please drop me a message — I prioritize those corrections.
Free. No Sign-Up. No Data Collection.
The calculator runs entirely in your browser. Nothing gets sent to a server — no inputs, no results, no analytics on what you're calculating. There are no accounts, no premium tiers, no "enter your email to unlock the full version." I genuinely do not understand why some sites make you create a login just to divide a number by 1.07, but here we are. This one's free, it stays free, and your data stays on your machine.
Disclaimer
These calculators are built for general reference and convenience. They're not a substitute for professional tax advice. Rate changes happen — especially at the local level — and you should verify the current combined rate for your specific location before relying on it for anything legally or financially significant.
If you're making business decisions, filing returns, or handling anything where a wrong number could actually cost you money, talk to a tax professional or check directly with your state's department of revenue.