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Sales Tax Calculator

This sales tax calculator helps you add tax to a purchase or work backward from a total receipt to find the untaxed amount.

Enter your numbers and review the live output

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Choose which sections to include, then copy the hosted iframe without moving the calculation logic into another codebase.

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Understand what this tool measures

It is built for quick checkout and pricing checks where users need to add sales tax or work backward from a receipt total without manual math. Supporting both directions makes it more useful than a single add-tax-only tool.

Choose whether you want to add tax or extract it from a final total, then enter the amount and tax rate. The calculator returns subtotal, tax amount, and total instantly.

Add-tax modeExtract-tax modeSubtotal and totalShareable results

What it measures

This calculator measures the pricing or profitability math behind sales tax calculator so the tradeoff is easier to read.

What affects the result

Cost, selling price, target margins, and the direction of the calculation all change the business outcome.

How people use it

People use the result to set prices faster, check profitability, and avoid making decisions from partial math.

How to keep the result

This sales tax calculator supports shareable URL state, so the current inputs can be copied into a link and reopened later without re-entering the scenario.

What the result means

Sales Tax Calculator updates results instantly as inputs change, then explains what the number means in plain language so the output is easier to act on.

How people use this calculator

Checkout estimate

Add 8.25% sales tax to a $120 purchase before paying.

The result shows the tax amount and the full total due.

Receipt breakdown

Extract 7.5% sales tax from a total receipt amount.

That helps recover the pre-tax price when only the final total is available.

Tell us if this calculator is working well

Use quick feedback if the result looks right or flag an issue if something seems off. Reports include the current calculator URL so the scenario can be reviewed.

Common questions

How do I add sales tax to a price?

Multiply the pre-tax amount by the sales tax rate to find the tax, then add that amount to the original subtotal.

What does extract tax mean?

Extract tax works backward from a total that already includes sales tax so you can estimate the untaxed subtotal and tax portion.

Can I use this for receipts and invoices?

Yes. It works for both adding tax before checkout and splitting tax out of a total afterward.