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

Sales Tax Calculator illustration
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Sales Tax Calculator

Calculate sales tax amount and total price, or extract tax from a tax-inclusive amount.

1

Choose Mode

Select "Add Tax" to calculate total with tax, or "Extract Tax" to find the pre-tax amount.

2

Enter Amount & Rate

Input the amount and tax rate (use preset buttons or enter custom rate).

3

View Breakdown

See pre-tax amount, tax amount, and total with clear formatting.

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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 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) rather than 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

  • 1
    Extracting tax: divide by (1 + rate), don't multiply by (1 − rate)
  • 2
    US sales tax varies by state, county, and city — check your local rate
  • 3
    Many countries include tax in displayed prices (tax-inclusive pricing)
  • 4
    Use the extract mode to find the pre-tax amount on receipts
  • 5
    Some items may be tax-exempt (groceries, medicine) depending on jurisdiction

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Frequently Asked Questions

Q How do I add sales tax to a price?
Multiply the price by (1 + tax rate as decimal). For 8.25% tax on $100: $100 × 1.0825 = $108.25.
Q How do I extract tax from a total?
Divide the total by (1 + tax rate as decimal). For an $108.25 total at 8.25%: $108.25 / 1.0825 = $100 pre-tax.
Q What is the difference between sales tax and VAT?
Sales tax is charged only at the final point of sale. VAT (Value Added Tax) is charged at each stage of production, with businesses reclaiming VAT paid on inputs.
Q Are all items subject to sales tax?
No. Many jurisdictions exempt necessities like groceries, medicine, and clothing. Tax-exempt items vary by location.
Q Why does extracting 10% tax from $110 give $100, not $99?
Because the 10% was calculated on $100, not $110. To reverse, divide by 1.10, don't subtract 10% of $110.

About This Tool

Sales Tax Calculator is a free online tool by FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration or installation required.