Sales Tax Calculator
Add or strip sales tax from any price, forwards or backwards.
About Sales Tax Calculator
Sales tax is calculated as the price multiplied by the tax rate. The final total is the original price plus that tax amount.
Formulas
Tax amount
Tax = Price × Rate
- P
- Pre-tax price
- r
- Tax rate (decimal)
Total price
Total = Price + Tax = Price × (1 + Rate)
- Total
- Final price including tax
Worked example
With the default values below, Sales Tax Calculator returns Total (with tax) of $108.25. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Price (before tax)accepts 0–1,000,000 $
- 100 $
- Sales Tax Rateaccepts 0–30 %
- 8.25 %
Results
- Total (with tax)
- $108.25
- Sales Tax
- $8.25
Step by step
- 1Pre-tax price= $100.00
- 2Calculate the tax amount: Tax = Price × Rate= $8.25
- 3Add tax to the price: Total = Price + Tax= $108.25
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- Estimates only. Confirm the exact applicable tax rate for your location.
- This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Sales Tax Calculator — full guide
What this works out
Sales tax is a single percentage added to a price at the till, charged by the state, county and often the city where the sale happens. You need the number before you reach the counter when a purchase is near a budget limit, when reimbursing an employee, when adding tax to an invoice you are issuing, or when a contractor quotes you a materials figure that is missing tax.
The calculator takes Price (before tax) (default 100) and Sales Tax Rate % (default 8.25), and shows the sales tax and the total with tax.
The arithmetic
- Tax = price × rate
- Total = price + tax = price × (1 + rate)
With the defaults: 100 × 0.0825 = 8.25 of tax, and a total of 108.25. The combined rate is the only genuinely difficult input — it is the sum of every jurisdiction that applies, and it changes. Many localities publish one combined figure, so enter that rather than adding the pieces yourself.
A less tidy example, a 249.99 item at the same 8.25%:
| Step | Calculation | Result |
|---|---|---|
| Tax | 249.99 × 0.0825 | 20.624175 |
| Tax, rounded to cents | — | 20.62 |
| Total | 249.99 + 20.62 | 270.61 |
Interpreting it
Treat the total as the cash you need and the tax line as money that is not yours — if you are the seller, you are collecting it on the state's behalf. The tax amount scales exactly with price, so the rate difference between two counties shows up most on large purchases: 2,400 of materials attracts 198 at 8.25% but 222 at 9.25%, a 24 swing from one percentage point.
Going the other way, divide the total by 1 plus the rate. 108.25 ÷ 1.0825 = 100 exactly.
What it does not cover
- Per-line rounding. Registers often round tax per item rather than once on the subtotal, so a long receipt can differ from this by a cent or two.
- Mixed baskets. Groceries, clothing and prescriptions are treated differently in different states. Enter only the taxable subtotal.
- Special levies. Prepared food, lodging and rental taxes sit on top of the general rate and are not included unless you build them into the rate you enter.
- Rate currency. Rates vary by place and change, so confirm the figure for your location rather than reusing an old one.
Check the price itself first with the discount calculator, since tax applies after a discount, and use the tip calculator for restaurant bills. For the credit-invoice systems used elsewhere, see the GST inclusive price calculator. Estimates only, not tax advice.
Estimates only. Confirm the exact applicable tax rate for your location.
Frequently Asked Questions
How do I find my sales tax rate?
Combine your state, county, and city rates. Many U.S. localities publish a single combined rate you can enter directly.
Can I work backwards from a total?
To find the pre-tax price from a total, divide the total by (1 + rate). For example, a $108.25 total at 8.25% is $108.25 / 1.0825 = $100.
Should I enter the rate where the store is or where the item is delivered?
For something shipped to you, most U.S. states look to the delivery address, so use your own combined rate. For something you carry out of the store, the store's rate applies. Rules differ by state and for online sellers, so confirm locally — a 2% difference on a 2,000 order is 40.
Some items in my cart are exempt — how do I handle that?
Split the cart. Add up only the taxable items and enter that subtotal, then add the exempt items to the result afterwards. If you enter the full cart, you overpay the estimate: a 200 basket with 80 of exempt groceries taxed at 8.25% would show 16.50 instead of the correct 9.90.
My receipt's tax is a cent off from this calculator — which is right?
Both are defensible. This calculator rounds once on the whole price you enter. Many point-of-sale systems compute tax line by line and round each one, and some states allow bracket tables instead of straight multiplication. Differences of a cent or two on a multi-item receipt are normal and not worth chasing.
How do I find the tax on a quote that only gives me the total?
Divide the total by 1 plus the rate to get the price, then subtract. A 540 total at 8.25% means 540 ÷ 1.0825 = 498.85 of price and 41.15 of tax. Do not take 8.25% of 540 — that gives 44.55, which is too high because the rate applies to the price, not the total.