Sales Tax Calculator

Choose Add tax when you know the pre-tax subtotal and want to calculate the sales tax amount and final price. Choose Reverse tax when you know the final tax-inclusive total and want to work backward to the subtotal and tax portion.

Enter the combined sales tax rate that applies to the transaction. The calculator does not guess a rate from your location because the correct rate can depend on state and local jurisdictions, sourcing rules, and whether the product or service is taxable.

Money is collected in cents, so reverse-tax arithmetic needs more care than displaying a long decimal. The reverse mode searches for a cent-valued subtotal that reproduces the entered final total after the tax is rounded to cents. That keeps the result closer to receipt-style arithmetic instead of pretending every transaction has infinite decimal precision.

In the United States, a purchase can be affected by more than one taxing jurisdiction. A combined sales tax rate may include state, county, city, or special-district components. Some states have no statewide general sales tax, while many states allow local rates on top of the state rate.

For that reason, a statewide percentage found in a general table may not be the rate that applies to a specific address or transaction. If accuracy matters for a real purchase, use the applicable state tax agency or official rate-lookup resource and then enter the combined rate here.

The arithmetic can be correct while the rate or taxable base is wrong. Groceries, clothing, digital products, services, medicine, prepared food, and other categories can be treated differently depending on the jurisdiction. Exemptions and sales-tax holidays can also change whether tax applies.

Sourcing rules determine which jurisdiction's rate applies to some transactions, especially delivery and remote sales. This calculator intentionally does not make those legal determinations. It calculates the numbers once you supply the rate and amount to model.

Retail systems do not all round in the same place. A merchant may calculate tax on each taxable line and then add the rounded amounts, while another system may calculate tax on a transaction-level taxable subtotal. Discounts, coupons, bundled products, shipping, and item-level taxability can also change the taxable base.

That means a one-cent difference does not automatically mean the percentage arithmetic is wrong. For a receipt audit, compare the taxable subtotal, applicable rate, and the merchant's rounding method.

Avery buys a $100 item at an entered sales tax rate of 8%. Tax is $8 and the checkout total is $108. In reverse mode, entering $108 and 8% recovers the $100 subtotal and $8 tax.

The reverse calculation divides by 1.08 rather than subtracting 8% of $108. Tax is based on the pre-tax amount, so simply subtracting the rate from the final total gives the wrong subtotal.

A combined sales-tax rate can include state and local components, but knowing the rate does not automatically tell you whether a particular product or service is taxable. Exemptions and sourcing rules can differ by jurisdiction and transaction.

That is why this calculator asks for the tax rate rather than inferring one from a ZIP code. Use a current state or local source when you need to determine the correct rate and taxability for a real purchase.

Reverse sales-tax math starts with a tax-inclusive total and a known rate, then solves for the pre-tax amount. It is useful when a receipt or quoted total includes tax but you need to separate the underlying price and tax amount.

The reverse result depends on the assumption that one uniform rate applies to the entire taxable amount. Mixed taxable and exempt items require line-item information rather than a single reverse calculation.

For discounts, markups, and general percentage math, use the Percentage Calculator. For restaurant gratuity and equal bill splitting, use the Tip Calculator and Bill Splitter.