Sales Tax / GST / VAT Calculator

How to use it

1. Enter the amount. Type the price you are starting from, e.g. 100. The currency does not matter, the calculator works with the plain number.
2. Enter the tax rate. Type the percentage that applies, such as 20 for 20% VAT, 10 for GST, or your local sales-tax rate like 8.25.
3. Pick how to treat the amount. Choose “excludes tax, add it” when your price is pre-tax and you want the total, or “includes tax, extract it” when your price already has tax baked in and you want to see how much.
4. Read the three cards. Net is the price before tax, Tax amount is the tax portion, and Gross is the full tax-inclusive total. They recalculate instantly as you type.

The formulas behind it

Sales tax, GST and VAT are all just a flat percentage applied to a price, so two small formulas cover every case. To add tax to a net price: tax = net × (rate ÷ 100) and gross = net + tax. With a net of 100 at 20%, that is 100 × 0.20 = 20 tax and a 120 gross.

To extract tax that is already inside a gross price, you cannot simply take the percentage of the gross, you have to divide it out: net = gross ÷ (1 + rate ÷ 100), then tax = gross − net. For a gross of 120 at 20%, that is 120 ÷ 1.20 = 100 net and 20 tax. A common mistake is taking 20% of 120 (which gives 24), that overstates the tax, because the 20% was charged on the net 100, not the 120 total.

Sales tax vs GST vs VAT

The names differ by region but the maths is identical. In the United States it is sales tax, set by state and local rates and added at checkout. In Australia, Canada, India, New Zealand and Singapore it is usually calledGST (Goods and Services Tax). Across Europe, the UK and much of the rest of the world it isVAT (Value Added Tax). Whichever applies to you, enter the rate and this tool handles it the same way, which is why it is labelled for all three.

Common real-world uses

• Quoting a client: add VAT or GST to a quoted net fee so you can show the all-in price.
• Reading a receipt: extract the tax from a gross total to see exactly how much went to tax.
• Bookkeeping: split a tax-inclusive expense into its net and tax parts for your records.
• Pricing products: work backwards from a target shelf price to the net amount you actually keep.

Frequently asked questions

Sales tax calculator by US state

Jump to a state to get its sales tax rate pre-filled:

• Alabama Sales Tax
• Alaska Sales Tax
• Arizona Sales Tax
• Arkansas Sales Tax
• California Sales Tax
• Colorado Sales Tax
• Connecticut Sales Tax
• Delaware Sales Tax
• Florida Sales Tax
• Georgia Sales Tax
• Hawaii Sales Tax
• Idaho Sales Tax
• Illinois Sales Tax
• Indiana Sales Tax
• Iowa Sales Tax
• Kansas Sales Tax
• Kentucky Sales Tax
• Louisiana Sales Tax
• Maine Sales Tax
• Maryland Sales Tax
• Massachusetts Sales Tax
• Michigan Sales Tax
• Minnesota Sales Tax
• Mississippi Sales Tax
• Missouri Sales Tax
• Montana Sales Tax
• Nebraska Sales Tax
• Nevada Sales Tax
• New Hampshire Sales Tax
• New Jersey Sales Tax
• New Mexico Sales Tax
• New York Sales Tax
• North Carolina Sales Tax
• North Dakota Sales Tax
• Ohio Sales Tax
• Oklahoma Sales Tax
• Oregon Sales Tax
• Pennsylvania Sales Tax
• Rhode Island Sales Tax
• South Carolina Sales Tax
• South Dakota Sales Tax
• Tennessee Sales Tax
• Texas Sales Tax
• Utah Sales Tax
• Vermont Sales Tax
• Virginia Sales Tax
• Washington Sales Tax
• West Virginia Sales Tax
• Wisconsin Sales Tax
• Wyoming Sales Tax
• District of Columbia Sales Tax

Results are rounded for display; for invoices, filings or accounting, double-check critical figures against official rates.