Sales Tax Calculator

What this sales tax calculator does

Sales tax is charged as a percentage of the price of a taxable good or service. This calculator works in both directions: it can add tax to a listed price, and it can remove tax from a total that already includes it.

The two directions answer different questions. Adding tax tells you what a shelf price will cost at the register. Removing tax tells you what you actually paid for the goods when all you have is the receipt total.

How to use this calculator

1. Choose Add sales tax if you have a pre-tax price, or Remove sales tax if you have a total that already includes tax.
2. Enter the price and the sales tax rate that applies to the purchase.
3. Click Calculate.

The default example is a $100.00 pre-tax price at 6.5%. The tax is $6.50 and the total is $106.50. Reversing the same numbers returns the $100.00 pre-tax price from the $106.50 total.

Sales tax formulas

Adding tax:

Tax = Pre-tax price × Rate / 100
Total = Pre-tax price + Tax

Removing tax:

Pre-tax price = After-tax total / (1 + Rate / 100)
Tax = After-tax total − Pre-tax price

What the results mean

• Before-tax price: the price of the goods before any sales tax.
• Sales tax amount: the tax collected at the stated rate.
• After-tax price: the amount paid at the register.
• Tax rate: the rate used, shown as a percentage.

Assumptions and limitations

The calculator applies a single flat rate to the whole amount. Real receipts often combine a state rate with county, city, and special district rates, and some items — groceries, prescription drugs, clothing in certain states — are exempt or taxed at a different rate. Shipping, discounts applied after tax, and use tax on out-of-state purchases are not modeled. Sales tax rates change; confirm the current rate with your state revenue department before relying on a figure for filing.

Frequently asked questions

Why can't I just subtract the tax rate from the total?

Because the rate applies to the pre-tax price, not the total. Subtracting 6.5% from $106.50 gives $99.58, which is wrong. Dividing by 1.065 gives the correct $100.00.

What is the difference between sales tax and VAT?

A sales tax is collected once, at the final sale to the consumer. A value-added tax is collected in stages along the supply chain, with businesses recovering tax paid on their inputs. The arithmetic for a single retail purchase is the same, but the reporting obligations are not.

Do all states charge sales tax?

No. Five states — Alaska, Delaware, Montana, New Hampshire, and Oregon — have no statewide general sales tax, though some local jurisdictions in Alaska do levy one. Rates and rules elsewhere vary widely.

How do I handle a discount?

Apply the discount to the pre-tax price first, then calculate tax on the reduced amount. If the discount is applied after tax, the tax was already computed on the full price.

Reference table

Example state sales tax rates

Rates are examples and change frequently. Some states have no statewide sales tax (for example, Oregon, Montana, New Hampshire, and Delaware). Verify the rate with the state revenue department or your local jurisdiction before relying on a result.

Source

References:

• IRS — State and Local Sales Tax
• U.S. Small Business Administration — Collect Sales Tax

Disclaimer

This calculator is for informational purposes only and is not tax advice. Sales tax rules vary by state and locality and change over time. Confirm the applicable rate and any exemptions with your state revenue department or a qualified tax professional.