A price tag doesn’t always tell the whole story. Sometimes tax is already inside the number, and sometimes it gets added at the till. This calculator handles both situations. Add tax to a price to see what you’ll pay, or take it out of a tax-inclusive price to see what the item cost before tax. It works for VAT, GST, sales tax or any percentage-based tax.
Choose what you want to do: add tax to a price, or remove tax from a price.
Enter the amount.
Enter the tax rate as a percentage.
Read the result. You’ll see the price before tax, the tax itself and the total.
If you’re not sure which mode to pick, look at the price you’re holding. If tax is not included yet, choose “add”. If the price already includes tax, choose “remove”.
Adding tax
Tax = price before tax × (rate ÷ 100)
Total = price before tax + tax
Removing tax
Price before tax = total ÷ (1 + rate ÷ 100)
Tax = total − price before tax
Adding tax. A laptop bag costs 200 before tax, and the tax rate is 20%.
Tax: 200 × 0.20 = 40
Total: 200 + 40 = 240
Removing tax. A receipt shows a total of 120 including 20% tax.
Price before tax: 120 ÷ 1.20 = 100
Tax: 120 − 100 = 20
A lower rate. An item costs 80 before tax at a 15% rate.
Tax: 80 × 0.15 = 12
Total: 80 + 12 = 92
When tax is already included, it’s tempting to take the percentage off the total. Don’t. On a total of 120 with 20% tax, 20% of 120 is 24, which would leave you with 96. The real pre-tax price is 100.
The reason is that the tax was calculated on the pre-tax price, not on the total. So you divide by 1.20, not subtract 20%. The calculator does this for you, which is the main reason to use it.
They all add a percentage to what you pay, but they’re collected differently.
VAT (value-added tax) and GST (goods and services tax) are charged at each stage of the supply chain. Businesses collect it from customers and can usually reclaim the tax they paid on their own purchases, so in the end the final buyer carries the cost. Prices in shops are normally shown with the tax already included.
Sales tax is added only at the final sale, usually at checkout, which is why the price on the shelf can be lower than what you pay at the till.
Rates and rules differ from one country, and sometimes one region, to another. Some goods, such as food, books or medicine, may have a reduced rate or none at all. Check the rate that applies to your purchase with your local tax authority or on your invoice.
Checking a receipt or invoice
Working out the pre-tax price of something you’re buying from a business
Pricing products if you sell online and need to show tax-inclusive prices
Comparing prices between shops that display tax differently
Estimating what a purchase will cost before you reach the checkout
Subtracting the percentage instead of dividing. As explained above, this gives the wrong pre-tax price.
Using the wrong rate. The standard rate isn’t always the one that applies. Check your invoice.
Adding tax twice. Make sure the price you’re entering isn’t already tax-inclusive before choosing “add”.
Rounding each line separately. On invoices with many items, rounding every line can leave you a few cents away from the official total. Follow the method your invoice or accounting software uses.
Does this work for sales tax as well as VAT?
Yes. The maths is the same for any percentage-based tax. Enter the rate that applies to you and the calculator does the rest.
How do I find out what rate to enter?
Look at your invoice or receipt, or check your local tax authority’s website. Rates change from time to time, so it’s worth confirming the current one.
Can I calculate the tax for several items at once?
Add the item prices together first, then enter the total. If the items are taxed at different rates, calculate each group separately.
Why is my invoice a few cents different from the result?
It’s usually rounding. Some systems round each item, others round the final total, which can produce small differences.
Is the result an official figure?
No. It’s an estimate to help you check and plan. For tax returns, invoicing or anything with legal weight, use official figures or speak to an accountant.
This calculator gives estimates for general information only and is not tax or financial advice. Tax rules and rates vary and change, so please confirm the details that apply to you with a qualified professional or your tax authority.