GST / Tax Calculator
Add or remove GST / sales tax and see the tax amount.
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Work out GST or sales tax in either direction. Enter a price and a tax rate to add tax to a net amount, or remove tax from a gross amount, and instantly see the tax portion and the final figure. It is handy for invoices, shopping and bookkeeping, and updates live in your browser.
Adding tax and removing tax are different sums
This is where most mistakes happen. Adding 18 percent tax to 1000 gives 1180, which is straightforward. But going the other way, finding the tax inside a 1180 total, is not 18 percent of 1180. You have to divide by 1.18 to recover the 1000 base, and the tax is the remainder. Taking a percentage off the total instead gives you the wrong figure every time, and it is a very common error on invoices.
Inclusive and exclusive pricing
A price quoted exclusive of tax has the tax added on top at checkout, which is normal in business to business dealings where the buyer reclaims it. A price quoted inclusive already contains the tax, which is standard in consumer retail. Confusing the two is how quotes come in unexpectedly high, so it is always worth confirming which basis a figure is on before agreeing to it.
Before you rely on a number
- Rates differ by country and often by product category within a country.
- Some goods are zero rated or exempt, and those are not the same thing for accounting.
- Rates change, so a figure from an old invoice may no longer apply.
- This is a general calculator and not tax advice. For filing, use your accountant or the official rates.
How to use GST / Tax Calculator
- 1
Enter the amount and tax rate.
- 2
Choose add tax or remove tax.
- 3
See the tax amount and total.
Frequently asked questions
Yes. Choose 'remove' to find the net price and the tax already included.