Sales Tax Calculator
Calculate sales tax, VAT, and the final total on any purchase
Enter a subtotal and a tax rate to instantly see the tax amount and the final total. Works for sales tax, VAT, or GST at any rate \u2014 the same formula applies regardless of country.
How to Use This Calculator
- Enter the pre-tax subtotal of your purchase.
- Enter your tax rate \u2014 sales tax, VAT, or GST, whichever applies where you are.
- Results update live as you type, showing the tax amount, the final total, and the exact formula used.
The Formula, With a Worked Example
Tax amount:Tax Amount = Subtotal × (Tax Rate ÷ 100)
Example: a $100 purchase at 8.5% tax is $100 × 0.085 = $8.50, for a final total of $108.50.
Working backward from a tax-included total:Subtotal = Total ÷ (1 + Tax Rate ÷ 100)
Example: a $108.50 total at 8.5% tax means the subtotal was $108.50 ÷ 1.085 = $100.
Sales Tax, VAT, and GST \u2014 What's the Difference?
Sales tax (common in the US) is added once, at the final point of sale. VAT (used across the EU and elsewhere) and GST (used in countries like Australia, India, and Canada) are collected at each stage of production, but the amount that shows up on a receipt for the end consumer works exactly the same way \u2014 as a percentage added to the price. This calculator applies the same formula regardless of which one applies to you; just enter your local rate.
Frequently Asked Questions
How do I calculate sales tax?
Multiply the subtotal by the tax rate as a decimal, then add that to the subtotal. A $100 purchase at 8.5% tax is $100 × 0.085 = $8.50 tax, for a total of $108.50.
What’s the difference between sales tax and VAT?
Sales tax is added once, at the final point of sale, and is common in the US. VAT (Value-Added Tax) is collected at each stage of production in many other countries, but the amount the end consumer sees on a receipt works the same way — as a percentage added to the price.
Does this calculator work for any country’s tax rate?
Yes — the calculator doesn’t assume a fixed rate. Enter your local sales tax, VAT, or GST percentage and it applies the same formula regardless of country.
How do I calculate the pre-tax price from a total that already includes tax?
Divide the total by (1 + tax rate as a decimal). A $108.50 total at 8.5% tax means the subtotal was $108.50 ÷ 1.085 = $100.
Can I use this for compound tax rates (state + local)?
Yes — add your state and local rates together first (e.g., 6% state + 2.5% local = 8.5%), then enter the combined rate as a single percentage.
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Last updated: September 20, 2026