Finance
Sales Tax Calculator
Add sales tax to a price or back it out of a gross total at any tax rate. Free, instant, and no signup — handy for invoices, receipts, and quotes.
Enter an amount and tax rate to calculate.
✳ Free · No signup · Runs in your browser — we never store your numbers
Small business guide
What this tool helps you do
Use this sales tax calculator to add tax to a pre-tax price or reverse sales tax from a tax-included total. It shows the net amount, tax amount, and gross total so invoices, receipts, quotes, and quick checks are easier to understand.
The math also works for VAT, GST, and other percentage-based consumption taxes. Everything happens in your browser.
How to use this tool
- 1
Choose the mode: "Add tax" (you have the pre-tax price) or "Reverse tax" (you have the total the customer paid).
- 2
Enter the price or total.
- 3
Enter the tax rate as a percentage (e.g. 8.25 for 8.25%).
- 4
See the breakdown instantly: net, tax, and total.
Formula
Add tax: Tax = price × (rate ÷ 100). Total = price + tax. Reverse tax: Net = total ÷ (1 + rate ÷ 100). Tax = total − net.
- Always use the exact local rate. Many places have combined state + county + city rates.
- Rounding: most jurisdictions round to the nearest cent. This calculator does standard half-up rounding.
- Some items are exempt or have reduced rates — check before quoting.
Examples
Adding sales tax to a quote
A contractor quotes $1,200 before tax in a state with 7.5% sales tax.
Inputs
- Mode: Add tax
- Price: $1,200
- Rate: 7.5%
Result
Tax: $90. Total due: $1,290.
Always show the customer the tax line separately on invoices.
Reversing tax from a receipt
You paid $108.50 total and the receipt says 8.25% tax was included.
Inputs
- Mode: Reverse tax
- Total: $108.50
- Rate: 8.25%
Result
Net (pre-tax): $100.23. Tax paid: $8.27.
Useful when you need the pre-tax amount for expense reports or margin calculations.
Key terms
Net / pre-tax price
The amount before sales tax is added.
Tax amount
The sales tax (or VAT/GST) portion.
Gross / total
The final amount the customer pays, including tax.
How to interpret the result
Tax is not profit
When you collect tax you are acting as an agent for the government. The tax portion does not count toward your revenue or margin.
Reverse tax is critical for accurate costing
If your bookkeeping or pricing model works on pre-tax numbers, always reverse the tax first before calculating margins or costs.
Rates change
City, county, and special district rates can change mid-year. Re-check the rate before large quotes or seasonal pricing updates.
Common mistakes
- Adding tax on top of an already tax-inclusive price.
- Using the wrong combined rate (state vs local).
- Treating collected tax as part of gross profit.
Frequently asked questions
Does this calculator handle multiple tax rates or exemptions?+
No. It is designed for a single flat percentage. For complex scenarios (tiered rates, exempt items, use tax), consult your accountant or local tax authority.
Can I use this for VAT or GST?+
Yes. The math is identical. Enter your local VAT/GST rate and use "Add tax" or "Reverse tax" as needed.
How accurate is the rounding?+
It uses standard JavaScript rounding to two decimal places (nearest cent). For production invoicing you may want to match your jurisdiction's exact rounding rules.