GST Calculator (Australia)

LAST UPDATE: September 25th, 2020

GST Calculator (Add Sales Tax)

Reverse GST Calculator (Subtract Sales Tax)

Definition – What is the GST?

The GST, or Goods and Services Tax, is a value-added tax on purchases.

As a value-added tax, only the final consumer pays the GST – purchases by business at other stages of production do not pay GST (they are charged GST, however, those charges act as a credit against the GST they charge).


Australia’s GST rate is 10%. Some goods and services are exempt from GST.

What goods and services are not charged GST?

The Australian tax office keeps a record of goods and services not charged GST.

Popular (but not all) categories are:

  • exports
  • basic food
  • medical care & medicines
  • international transportation

Imports of goods (including low-value goods) to Australia are charged GST as of July 2018.

Formula – How to calculate GST (formula)

GST is calculated by multiplying the GST rate (10% in Australia) by the total pre-tax cost. The cost of GST is then added to the purchase.

Example: $75 of goods x 10% GST = $7.50 GST

$75 of goods + $7.50 GST = $82.50 total

How to calculate reverse GST (formula)

To find the GST from a total, divide the total amount by the GST rate divided by 100 and plus 1.

Example: $70 total (with GST) at 10% GST rate

(10% / 100) + 1 = 0.1 + 1 = 1.1

$70 / 1.1 = $63.64 cost before GST

GST refunds (tourism & business)

Tourists who purchase goods with GST are eligible for a refund on exit of the country via the tourist refund scheme (TRS).  Goods purchased within the last 60 days of travel can qualify for a refund of GST.

Businesses are eligible to reclaim their costs that include GST. For more information and how to register see the Australian Tax Office’s page on GST.

Sources and more resources