Using the GST rate
myIR will tell you how much GST you have to pay or will be refunded. If you file a paper return, the form tells you what calculations to make.
You can find examples of how to use the GST rate calculations below.
What GST is
Paying GST
GST refunds
Hine sells headphones for $100 not including GST. They need to work out how much GST to add to the price. The rate of GST is 15%, so they multiply the $100 price by 0.15 and get $15. Hine can add $15 to the original $100 price. The total price is $115 including GST.
Arthur needs to know what the price of the headphones was before Hine added GST. Arthur takes the total price with GST, $115, and multiplies it by 3. They divide that total by 23 and get $15. This is the GST part of the total price. Arthur takes away the GST amount, $15, from the total price, $115, and gets $100. The original price was $100 not including GST.