Sales Tax Calculator
Sales Tax Calculator is a free finance tool that runs directly in your browser with no account required.
About this tool
This calculator adds sales tax to a price or strips it back out of a tax-inclusive total. It handles quantity and a pre-tax discount, reports the taxable amount and effective rate, and shows a small scenario table with the tax computed at nearby rates. The scenarios can be downloaded as a CSV.
How to use
- Enter the Price of one item and your local Tax rate %.
- Adjust Quantity and any Discount % applied before tax.
- Choose Mode: Add tax to a pre-tax price, or Remove tax to back out the pre-tax amount from a total.
- Read the subtotal, sales tax, and total, and use Download tax scenarios CSV to compare rates.
Frequently asked questions
How does "Remove tax" mode work?
It treats your price as tax-inclusive and divides by (1 + rate) to recover the pre-tax amount, then reports the embedded tax. This is useful for receipts that only show a final total.
Is the discount applied before or after tax?
Before. The discount reduces the taxable amount, and tax is calculated on the discounted subtotal, which matches how most US retailers handle coupons.
What rates appear in the scenario table?
Your entered rate plus versions 2 percentage points lower and higher, so you can quickly compare jurisdictions or check the impact of a rate change.
What input limits apply?
Price and tax rate cannot be negative, the rate must be 100% or less, the discount caps at 99%, and quantity is rounded down to a whole number of at least 1.
Do my prices get sent to a server?
No — the math and the CSV generation happen entirely in your browser.
Will this match my exact register receipt?
Usually within a cent, but rounding rules, item-level taxability, and local surtaxes vary, so treat results as estimates rather than tax advice.