GST Calculator
Add or remove GST/VAT from a price.
Results update as you type.
This calculator is for general guidance only and is not tax advice. Rules vary by jurisdiction and year; confirm with a qualified professional.
How it works
Goods and services tax, known as GST in countries like Australia, India, Canada, and New Zealand and as value-added tax, or VAT, across Europe and much of the world, is a consumption tax added as a percentage of a product's price. This GST calculator works in both directions: it can add tax to a net, pre-tax amount to find the final price a customer pays, or remove tax from a gross, tax-inclusive amount to recover the underlying price and the tax hidden within it. Getting the reverse calculation right is where many people slip up, because you cannot simply subtract the rate from a tax-inclusive price; instead you divide by one plus the rate. The calculator returns the tax amount alongside both the net and gross figures, so whichever number you start from, you see the complete breakdown. This is invaluable for small business owners issuing invoices, freelancers quoting prices, shoppers checking receipts, and accountants reconciling tax. Because rates differ by country and sometimes by product category, you enter whatever rate applies. Enter the amount, choose whether it already includes tax, and set the rate to get an instant, accurate split of price and tax.
add: gross = net × (1 + rate); remove: net = gross / (1 + rate)
Goods and services tax is a percentage added to the pre-tax price. To add GST, multiply the net amount by one plus the rate to get the gross, tax-inclusive price, with the tax itself being the net times the rate. To remove GST from a tax-inclusive price, divide the gross by one plus the rate to recover the net amount, and the difference is the embedded tax. Reversing the calculation correctly is what trips most people up.
Source:Standard value-added tax calculation
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter amount, gst/vat rate and direction.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
GST/VAT amount updates instantly as you type — no button to press.
Frequently asked questions
How do I add GST to a price?
Multiply the net, pre-tax amount by the GST rate to get the tax, then add it to the net price to get the gross, tax-inclusive total. For a hundred-dollar item at ten percent, the tax is ten dollars and the final price is a hundred and ten. Select the add option in the calculator and it does this automatically, showing the tax and both totals.
How do I remove GST from a total?
To find the pre-tax price hidden inside a tax-inclusive total, divide the gross amount by one plus the rate, not by subtracting the rate. For a gross of a hundred and ten at ten percent, dividing by 1.1 gives a net of a hundred, and the embedded tax is ten. Choosing the remove option in the calculator handles this reverse calculation correctly.
What is the difference between GST and VAT?
GST and VAT are essentially the same kind of tax under different names: both are consumption taxes charged as a percentage of price at each stage of the supply chain, with businesses reclaiming the tax they pay on inputs. GST is the term used in countries like Australia, Canada, and India, while VAT is used across Europe and elsewhere. The maths is identical.
Why can't I just subtract the rate to remove GST?
Because the tax was applied to the smaller net amount, not the larger gross amount. Subtracting ten percent from a gross price removes ten percent of the gross, which is more than the tax actually charged on the net. The correct method divides the gross by one plus the rate, which properly reverses the original multiplication and recovers the true pre-tax price.
Does the GST rate vary by country?
Yes. Rates differ widely: Australia and Singapore have used single-digit or low double-digit GST, many European VAT rates sit around twenty percent, and some countries apply reduced rates to essentials like food and books. Certain goods may be exempt or zero-rated. This calculator lets you enter whatever rate applies to your country and product so the result matches your local rules.