Sales Tax Calculator
Calculate sales tax and the final price of a purchase, or reverse a tax-inclusive total to find the amount before tax. Add quantity, a pre-tax discount and optional non-taxable charges to plan checkout costs with a clear breakdown.
Calculate sales tax online
Start with the pre-tax unit price. Discount is applied before tax in this simplified estimate.
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A mathematical estimate using the rate you enter. Jurisdiction-specific taxability, exemptions, shipping rules and invoice-level rounding may differ.
Sales tax formula: tax = taxable price × (tax rate ÷ 100). Final price = taxable price + sales tax. To remove tax from an inclusive price: pre-tax price = inclusive price ÷ (1 + tax rate ÷ 100). Example: $100 × 8.25% = $8.25 tax; total = $108.25.
What is a sales tax calculator?
A sales tax calculator helps you work out how much tax will be added to a purchase and what you will pay at checkout. It can also reverse the calculation when a receipt or displayed price already includes tax, separating the pre-tax amount from the tax component.
For an accurate estimate, you need the correct tax rate and must know whether an item or charge is taxable. Sales tax is often used in the United States, where the applicable rate and exemptions can depend on state, local jurisdiction, product and other rules.
How to use this sales tax calculator
- Select Add sales tax if the price is before tax, or Remove sales tax if your unit price already includes tax.
- Enter the price per item, applicable sales tax rate and number of identical items.
- In Add mode, optionally enter a discount percentage that reduces the taxable price.
- If needed, add non-taxable shipping or other extra charges once for the entire purchase.
- Choose your currency for display and click Calculate tax.
- Read the pre-tax amount, tax, final cost and calculation steps.
Sales tax formula: how to add tax
Sales tax
Tax = taxable amount × (rate ÷ 100)
Price after tax
Total = taxable amount + tax
Remove tax
Before-tax price = inclusive total ÷ (1 + rate ÷ 100)
To calculate tax on several identical items, multiply the per-item price by the quantity. When the applicable rules allow a discount to reduce the taxable selling price, subtract that discount before applying the tax percentage. In this tool, optional shipping/other charges are added after tax and are treated as non-taxable.
Sales tax calculation example: $100 at 8.25%
Suppose a product costs $100 before tax and a single applicable tax rate is 8.25%. Multiply 100 by 0.0825 to find $8.25 in tax. Add that to the original price to get the final cost of $108.25.
| Example | Calculation | Result |
|---|---|---|
| Before-tax price | Entered amount | $100.00 |
| Tax rate | Illustrative rate | 8.25% |
| Sales tax | $100 × 0.0825 | $8.25 |
| Final price | $100 + $8.25 | $108.25 |
| Reverse calculation | $108.25 ÷ 1.0825 | $100.00 before tax |
The 8.25% rate is an example, not a live or universal rate for any particular city. Enter the tax rate that applies to your own transaction.
Reverse sales tax calculator: remove tax from a total
If your receipt shows a tax-inclusive amount, you should not simply subtract the tax percentage from that total. The percentage was applied to the pre-tax price, not to the amount after tax. To work backwards, divide the inclusive price by one plus the tax rate expressed as a decimal.
For example, with a tax-inclusive unit price of $108.25 and an 8.25% rate, the base price is $108.25 ÷ 1.0825 = $100.00. The tax portion is $108.25 − $100.00 = $8.25. Select Remove sales tax in the tool to perform the reverse calculation.
How to calculate sales tax after a discount
When a discount legally reduces the taxable selling price, apply the discount to the item's pre-tax price first. For example, two items at $100 each with a 10% discount have a pre-tax list subtotal of $200 and a $20 discount. The taxable amount is $180, and at an assumed 8.25% rate the calculated tax is $14.85. The total after tax is $194.85, excluding other charges.
However, retailer coupons, manufacturer coupons, rebates and discounts can be treated differently under local tax law. This page models a straightforward percentage discount that reduces the taxable price; it cannot decide whether a particular promotion has that treatment.
How sales tax rates work in the United States
US sales tax rules are not uniform across the country. Some jurisdictions impose a state tax, local taxes or special district taxes, while certain goods and services may qualify for exemptions. The applicable combined rate can vary by location and the transaction's tax-sourcing rules.
Check the relevant tax authority rather than treating a sample rate as a current legal rate. The Streamlined Sales Tax state contact directory provides links to individual state tax agencies; California's tax guidance illustrates how district-level rates can differ.
Sales tax vs GST vs VAT
Sales tax
Often charged at the retail sale in US jurisdictions. The governing rate and taxability depend on the relevant location and product or service.
GST
Goods and Services Tax is India's indirect tax system for many goods and services. Rates and compliance rules depend on classification and applicable law.
VAT
Value-added tax generally applies through multiple stages of supply under a jurisdiction's own accounting and credit rules.
The simple add/remove-percentage arithmetic can also help with an illustrative GST- or VAT-inclusive price, but that does not make the legal systems equivalent. In India, verify the applicable product or service classification and rate using the Central Board of Indirect Taxes and Customs (CBIC) guidance and current notifications. This calculator does not determine CGST, SGST, IGST, exemptions, input credits or filing obligations.
Are shipping and handling charges subject to sales tax?
Shipping and handling charges can be treated differently depending on the jurisdiction, what was sold and how charges appear on the invoice. The optional extra-charge field on this calculator assumes those charges are not taxable and adds them after computing tax on the goods.
If shipping or another fee is taxable for your transaction, include it in the taxable base using an appropriately adjusted price or calculate the tax separately under the applicable local rules. Do not rely on a generic formula as a substitute for jurisdiction-specific guidance.
Common sales tax calculation mistakes
- Subtracting 8% from a tax-inclusive price: reverse tax uses division by 1.08, not subtraction of 8% from the inclusive amount.
- Assuming one rate applies everywhere: local taxes and product exemptions can change what applies.
- Ignoring the quantity: tax on a multi-item purchase generally depends on the taxable value of all relevant items.
- Discounting after tax without checking rules: coupon and discount tax treatment can vary.
- Automatically taxing or exempting delivery charges: check local rules for shipping, freight and handling.
- Expecting all receipts to round identically: per-item versus invoice-level rounding can cause small differences.
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Frequently Asked Questions
How do I calculate sales tax?
Multiply the taxable price by the rate divided by 100. For example, $100 at 8.25% creates $8.25 in tax and a total of $108.25.
How do I remove tax from a price?
Divide the tax-inclusive amount by 1 plus the rate expressed as a decimal. Subtract that base price from the inclusive amount to obtain the tax.
Do you calculate state and local tax automatically?
No. Enter the appropriate combined rate yourself. The calculator does not perform jurisdiction lookup or check product taxability.
Is a discount applied before tax?
This tool's Add Tax mode treats an entered discount as reducing the taxable base. Actual tax treatment of certain coupons or rebates can differ.
Is sales tax the same as GST or VAT?
No. They are different tax systems. The basic mathematical percentage calculation can look similar, but rates, exemptions and compliance rules differ.
Does it tax shipping fees?
No. Optional shipping or other charges are assumed non-taxable and are added after the calculated sales tax.
Why does my receipt differ by a few cents?
Merchants and authorities may apply specific rounding conventions, per-item rules, taxable classifications or discount treatments. This tool is an educational estimate.
Last updated: October 18, 2026. Calculations are illustrative and use the rate provided by the user. This calculator does not provide live tax rates, determine legal tax obligations, or replace guidance from an applicable tax authority.