GST calculator
GST component
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General information only. Some goods and services are GST-free or input taxed.
Quick answer
Enter any dollar amount and choose whether it includes or excludes GST. The calculator shows the GST component, the amount excluding GST and the amount including GST, to the cent, at Australia's standard 10% rate. To remove GST from an inclusive price it divides by 11; to add GST it multiplies the ex-GST figure by 1.1.
Key points
- GST in an inclusive price is one eleventh of it, not 10% of it
- Businesses must register once GST turnover reaches $75,000 ($150,000 for non-profits)
- The GST in your bank balance belongs to the ATO until your BAS is paid
- Lenders reading bank statements see turnover including GST
Australian GST is 10% of the price before tax. That means the GST hidden inside a GST-inclusive total is one eleventh of the total, a detail that trips up even experienced owners when they’re quoting in a hurry. Type an amount, tell the calculator whether GST is already in it, and you’ll have all three figures to the cent.
Two inputs, four results
Amount. Any dollar figure: a quote, an invoice, a supplier bill or a quarter’s sales.
This amount includes GST / excludes GST. Pick “includes” when the figure is what the customer pays. Pick “excludes” when you’re starting from your own price and need to add tax on top.
The results panel then shows:
| Result | What it tells you |
|---|---|
| GST component | The tax inside (or to add to) the amount |
| Amount excluding GST | Your revenue or cost before tax |
| Amount including GST | What the customer pays, or what you pay the supplier |
| Rate used | Always the standard 10% Australian rate |
There’s no option for GST-free or input-taxed items. If an invoice mixes taxable and GST-free lines, run only the taxable part through the calculator.
Quick reference: common amounts
| Starting amount | GST | Excluding GST | Including GST |
|---|---|---|---|
| $82.50 including GST | $7.50 | $75.00 | $82.50 |
| $550 including GST | $50.00 | $500.00 | $550.00 |
| $1,000 including GST | $90.91 | $909.09 | $1,000.00 |
| $1,000 excluding GST | $100.00 | $1,000.00 | $1,100.00 |
| $2,750 including GST | $250.00 | $2,500.00 | $2,750.00 |
Two of those figures line up with ATO tax invoice rules. According to the ATO, if a customer asks for a tax invoice you need to provide one within 28 days, unless the sale was $82.50 or less including GST. Once a sale reaches $1,000 or more, the invoice also has to show the buyer’s identity or ABN. Our glossary entry on the tax invoice covers the other required details.
A quarter’s worth of GST, worked through
A landscaping business invoices $66,000 including GST across a quarter. In the same three months it pays $22,000 including GST for plants, soil, fuel and equipment hire.
- Run $66,000 with “includes GST”: GST collected is $6,000.
- Run $22,000 with “includes GST”: GST credits are $2,000.
- The difference, $4,000, is roughly what goes on the BAS as GST payable.
That $4,000 has been sitting in the business account all quarter, looking like spare cash. It isn’t. Owners who treat it as working capital are the ones who find a BAS they can’t pay. A simple habit helps: each time a customer pays, move one eleventh into a separate account.
If the quarter has already got away from you, there are ways through. Our page on funding for BAS and GST explains the options, and you can ask us about yours without it touching your credit file.
Why GST matters when you apply for finance
GST isn’t just a tax question. It shapes how a lender sees your numbers.
- Bank statements include it. Lenders who assess on bank statements see deposits including GST. Your profit and loss shows sales excluding GST. A business with $1.1 million coming through the account may be reporting $1 million of sales, and that’s normal.
- GST owed counts as a debt. On a balance sheet, GST collected but not yet paid is a current liability. It lowers your working capital ratio, so lodging and paying on time keeps that ratio honest.
- Late BAS raises questions. Credit teams often pause a file when activity statements haven’t been lodged. See business loans when BAS lodgements are late.
- ATO debt isn’t a dead end. Banks are often the cheapest lender when everything is up to date, and it’s worth starting there. If GST has built up into an ATO debt, specialist lenders regularly fund clearing it. Our guide to ATO tax debt business loans walks through how.
- Not registered? Smaller businesses under the threshold can still borrow. Lenders simply look for other evidence of turnover: see business loans when you’re not registered for GST.
Who has to register?
According to business.gov.au, you must register for GST once your GST turnover (business income, less certain sales, not profit) reaches $75,000. The threshold is $150,000 for non-profit organisations. Taxi, limousine and ride-sourcing drivers must register whatever their turnover, as must businesses claiming fuel tax credits. You need to register within 21 days of realising you’ll cross the line. Registering voluntarily below the threshold is allowed, but then you charge GST and lodge activity statements like everyone else.
What the calculator doesn’t do
It doesn’t decide whether a sale is taxable, GST-free or input taxed; that depends on what you sell and to whom. It doesn’t handle imports, the margin scheme for property or GST on second-hand goods. And it rounds to the cent per amount, while your accounting software may round per line. For anything beyond a straightforward taxable sale, your accountant or the ATO is the right call.
Related calculators
- Margin and markup calculator: price your work so the margin survives GST and costs.
- Break-even calculator: the sales you need each month, using ex-GST prices.
- ATO debt calculator: what a payment plan would look like if GST has piled up.
When the BAS is bigger than the bank balance
Plenty of good businesses get caught by GST: a big quarter, a slow-paying client and suddenly the activity statement is due with not enough in the account. We see it often and we don’t judge it.
If you’d like to talk through the options, the enquiry takes about a minute to complete. It’s not a credit application, so your credit report stays untouched. Your enquiry isn’t broadcast to a queue of lenders hoping one bites. Someone here studies it and rings to explain what’s realistic. Exact figures for the amount owed and your monthly takings let us steer you to a workable fix sooner.
Frequently asked questions
How do I work out GST from a total that already includes it?
Divide the total by 11. A $1,100 invoice contains $100 of GST and $1,000 of price. Taking 10% of $1,100 would give $110, which is wrong, because GST was added to the ex-GST price, not the total.
When do I have to register for GST?
According to business.gov.au, a business must register once its GST turnover reaches $75,000, or $150,000 for a non-profit. Taxi, limousine and ride-sourcing drivers must register whatever their turnover. You have 21 days to register after you become aware you'll cross the threshold.
Does every sale include GST?
No. Some sales are GST-free, such as most basic food and many medical and education services, and some are input taxed, such as residential rent and most financial supplies. The calculator always applies the standard 10%, so leave GST-free items out of the amount.
Is there GST on business loan interest?
Interest on a loan is generally an input-taxed financial supply, so no GST is charged on it and there's no credit to claim. Some fees around a loan, such as certain broker or valuation fees, can include GST, so check each invoice.
Do lenders look at turnover with or without GST?
Lenders who assess bank statements see deposits including GST, while your profit and loss statement and tax returns usually show sales excluding GST. Good credit teams adjust for this, but it helps to know why the two figures differ by roughly a tenth.