Add sales tax to a price, or work backwards from a tax-inclusive price to find the amount before tax. Enter the price and the tax rate to see the tax and the total.
Sales Tax Calculator
How the Sales Tax Calculator Works
This calculator works out the sales tax on a purchase and the total you actually pay at the till. Enter the price before tax and your local tax rate, and it shows the tax amount and the final price. It is used for budgeting a purchase, checking a receipt, and comparing prices between places with different tax rates.
The maths is straightforward: Sales tax = Price × Rate ÷ 100, and Total price = Price + Sales tax. If you know the total price including tax and want to find the pre-tax price, the calculator reverses it: Price before tax = Total price ÷ (1 + Rate ÷ 100). The rate you enter should be the combined rate for your area — state, county, and city taxes added together where they all apply.
The calculator assumes a single flat tax rate applied to the full price. It does not handle exemptions, reduced rates for certain goods, or tiered systems. If some items in a basket are taxed differently, calculate them separately and add the results.
How to Use This Calculator
- Enter the price before tax.
- Enter the sales tax rate as a percentage.
- Press Calculate.
- Read the tax amount and the total price including tax.
- To work backwards from a tax-inclusive price, use the reverse calculation described above.
Example
A $200 item with a 7.5% sales tax carries $15.00 of tax, for a total of $215.00.
A $1,000 laptop at 8.25% costs $82.50 in tax, bringing the total to $1,082.50. The same laptop in a state with no sales tax costs exactly $1,000 — which is why the rate matters so much to the final price.
What Affects the Result
- Price before tax — tax scales directly with the price.
- Tax rate — the combined local rate; this varies widely by state and city.
- Exemptions — some goods (groceries, medicine, clothing in some places) may be exempt or taxed at a lower rate.
- Rounding — tax is usually rounded to the nearest cent, which can shift the total by a cent or two.
- Practical tip — when comparing prices online versus in a store, include the tax: an online price without tax is not directly comparable to a shelf price with tax included.
The combined rate is where most mistakes happen, because shoppers often enter only the state rate and forget the rest. In the United States, the rate at the till is usually the state rate plus a county rate plus a city rate, and those extras can add several percentage points: a state rate of 6% might become 9.5% at the register once local taxes are included. Before you calculate a big purchase, check the total combined rate for the exact place you will buy — your state’s revenue department usually publishes a lookup by address — and enter that figure, not just the headline state rate. The difference on a $2,000 purchase between 6% and 9.5% is $70, which is worth a minute of checking.
It is also worth knowing that “tax-free” shopping is rarely quite what it sounds like. A state with no sales tax still funds itself somehow — often through higher property or income taxes — and an online seller may charge tax based on where you live rather than where the seller is. If you are buying while travelling, the rate that applies is generally the rate where you take delivery, not where you live. Keep that in mind when a bargain in another state looks too good: the tax at the till may follow you home.
Sales Tax Calculator FAQs
How do I calculate sales tax?
Multiply the pre-tax price by the tax rate as a decimal. For example, $200 at 7.5% gives $200 × 0.075 = $15.00 of tax, for a total of $215.00.
What is the difference between the price before and after tax?
The price before tax is the shelf or list price. The price after tax adds the sales tax to it — that is the amount you actually pay.
How do I find the pre-tax price from the total?
Divide the total by 1 plus the rate as a decimal. For a $215 total at 7.5%, the pre-tax price is $215 ÷ 1.075 = $200.00.
Why does sales tax vary so much?
Because rates are set locally. States, counties, and cities each set their own rates, so the combined rate at the till depends on exactly where you buy.
Are all goods taxed at the same rate?
No. Many places exempt or reduce tax on essentials such as groceries and medicine, while other goods carry the full rate. Check your local rules for the item you are buying.
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