Add GST
Multiply the ex-GST amount by 10% for the GST component and add it to the original amount. For $100 ex GST, GST is $10 and the total is $110.
Free Australian GST calculator
Add GST or find the GST already in a total.
Use this calculator for amounts fully subject to Australia’s standard 10% GST rate. Check with your accountant or the ATO for your situation, including GST-free or mixed sales.
GST calculator
All money is in AUD. Calculations stay in your browser; inputs are not sent anywhere or saved. Defaults are editable examples.
- Amount ex GST
- $100.00
- GST (10%)
- $10.00
- Amount inc GST
- $110.00
How to use this calculator
Find included GST
Divide a fully GST-inclusive amount by 11 for its GST component, then subtract that component for the ex-GST amount. The GST inside $110 is $10, not $11.
Check the treatment
This tool assumes the whole amount is subject to 10% GST and rounds money to cents. Check with your accountant or the ATO for your situation. Read the ATO GST guide for current information.
Do this automatically in Nenvik
Nenvik lets authorised staff prepare and issue invoices from jobs, keeping the invoice connected to the work record. Check the invoice details before issue.
Frequently asked questions
What GST rate does this use?
It uses the Australian standard rate of 10% for a fully taxable amount. Some sales have a different GST treatment.
Why divide a total by 11?
A fully taxable total has 100 parts of price and 10 parts of GST. GST is 10 out of 110 parts, or one eleventh of the total.
Does this decide whether I should charge GST?
No. Check your registration and the treatment of your sale with your accountant or the ATO.
Are my figures saved or sent anywhere?
The calculator runs in your browser. Its inputs are not sent anywhere or saved in browser storage. Reloading resets the figures.
Related guides
Keep the invoice connected to the job.
Create an account to prepare and issue invoices against your job records.