Sales Tax CalculatorCalculate sales tax amount and total price, or extract tax from a tax-inclusive amount.

Sales Tax Calculator
Calculate sales tax amount and total price, or extract tax from a tax-inclusive amount.
Choose Mode
Select "Add Tax" to calculate total with tax, or "Extract Tax" to find the pre-tax amount.
Enter Amount & Rate
Input the amount and tax rate (use preset buttons or enter custom rate).
View Breakdown
See pre-tax amount, tax amount, and total with clear formatting.
What Is Sales Tax Calculator?
A sales tax calculator computes the tax amount and total price for any purchase, or reverses the calculation to extract tax from a tax-inclusive amount. In "Add Tax" mode, it calculates: Total = Amount × (1 + Tax Rate%). In "Extract Tax" mode, it finds: Pre-tax Amount = Total / (1 + Tax Rate%), Tax = Total − Pre-tax Amount. The calculator includes preset buttons for common tax rates making it quick to use for your location. Sales tax rates vary significantly by jurisdiction — from 0% in some US states to over 20% in some European countries (as VAT). Understanding how tax affects pricing is important for budgeting, business accounting, and international commerce.
Why Use Our Sales Tax Calculator?
- Two modes: add tax or extract tax from inclusive price
- Quick preset buttons for common tax rates
- Clear breakdown of pre-tax, tax, and total amounts
- Works for any tax rate worldwide
- Essential for business and personal finance
Common Use Cases
Shopping
Calculate the total cost including sales tax before checkout.
Accounting
Extract the pre-tax amount and tax component from invoices.
Pricing
Set tax-inclusive prices that result in round numbers after tax extraction.
Travel
Calculate prices with local tax rates when shopping in different jurisdictions.
Technical Guide
Tax-exclusive calculation: Tax = Amount × (Rate/100), Total = Amount + Tax = Amount × (1 + Rate/100). Tax-inclusive (reverse) calculation: Pre-tax = Total / (1 + Rate/100), Tax = Total − Pre-tax. The key insight is that adding tax and extracting tax are inverse operations. If you add 10% to $100 you get $110. Extracting 10% from $110 gives back $100 (not $99 — a common mistake). The correct extraction formula divides by (1 + rate), not multiplying by (1 − rate). For business accounting, the tax component of a tax-inclusive price is: Tax = Total × Rate / (100 + Rate). These formulas apply to any proportional tax: sales tax, VAT, GST, or service tax.
Tips & Best Practices
- 1Extracting tax: divide by (1 + rate), don't multiply by (1 − rate)
- 2US sales tax varies by state, county, and city — check your local rate
- 3Many countries include tax in displayed prices (tax-inclusive pricing)
- 4Use the extract mode to find the pre-tax amount on receipts
- 5Some items may be tax-exempt (groceries, medicine) depending on jurisdiction
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Frequently Asked Questions
QHow do I add sales tax to a price?
QHow do I extract tax from a total?
QWhat is the difference between sales tax and VAT?
QAre all items subject to sales tax?
QWhy does extracting 10% tax from $110 give $100, not $99?
About Sales Tax Calculator
Sales Tax Calculator is a free online tool from FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration required. No ads. Just fast, reliable tools.







