GST Calculator Australia — Add or Remove 10% GST

Add 10% GST to a price, or take the GST out of a GST-inclusive total by dividing by 11 — the official method on the government's own calculator. Free, instant, and shown line by line.

AmountPrice excluding GST

Price excluding GST$100.00

GST (10%)$10.00

Price including GST $110.00

Standard rate: 10% since 1 July 2000 (ATO).

What this result means for you

The price excluding GST is $100.00, the 10% GST adds $10.00, and the GST-inclusive total is $110.00. To go back the other way later, divide the total by 11 to find the GST — or switch this calculator to Remove.

Percentage trap: subtracting 10% from $110.00 gives $99.00 — off by $1.00 from the correct $100.00. Adding 10% and subtracting 10% are not opposites. Divide by 1.1, or use ÷11.

Includes your calculation, the Australian Magic Numbers (×1.1 and ÷11) and ready-to-paste Excel formulas. Pure client-side — no data leaves your browser.

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How to Calculate Australian GST in 3 Steps

Enter your amount

Type the price excluding GST (Add mode) or the GST-inclusive total (Remove mode).

Pick add or remove

Add 10% GST to a quote or price, or pull the GST out of a total by dividing by 11.

Read the result line by line

The price excluding GST, the GST amount and the GST-inclusive total appear instantly — copy them or download the CSV.

Australia's GST Rate: 10% Since 1 July 2000

Australia charges a single flat GST rate of 10% on most goods and services. It is a federal tax, so the rate is identical in every state and territory — NSW, Victoria, Queensland and the rest all pay the same 10%. The rate has never changed since GST started on 1 July 2000: a push to lift it to 15% in 2015 and another to 12.5% in 2019 both went nowhere. Not everything carries GST, though. GST-free items include most basic food, some education courses and materials, some medical and health products, exports, and menstrual products. Residential rent and most financial services are "input-taxed", which also means no GST is added to the price. Businesses must register for GST once turnover reaches $75,000 a year ($150,000 for non-profits), and taxi or ride-sourcing drivers must register no matter how little they earn. This page lists its official sources and the date the rate was last verified.

Why GST Is the Total ÷ 11 — Not 10% of the Total

Here is the puzzle this rule solves: you buy something for $20 and the receipt shows $1.82 of GST. Why not $2.00? Because the 10% was charged on the price before GST, not on the total you paid. Think of the before-GST price as 100%. Add 10% GST and the total becomes 110%. The GST is therefore 10 parts out of 110 — exactly one eleventh of the total, which is about 9.09%, not 10%. That is why the government's Moneysmart calculator says to divide a GST-inclusive cost by 11 to find the GST: $20 ÷ 11 = $1.82, and the before-GST price was $18.18. Dividing by 11 gives the same answer as dividing the total by 1.1 and subtracting — it just gets there in one step. This calculator uses ÷11 and shows you the working.

How This Calculator Works (the Formulas)

Add mode treats your amount as a price excluding GST: the GST is 10% of it (multiply by 0.1), and the total is the amount × 1.1. The government's own worked example: a $1,000 price collects $100 of GST for a $1,100 total. Remove mode treats your amount as a GST-inclusive total: the GST inside it is the amount ÷ 11, and the price excluding GST is what is left — the same answer as dividing by 1.1. So a $1,000 GST-inclusive price contains $90.91 of GST and was $909.09 before GST. One warning before you reach for a shortcut: never subtract 10% to remove GST. $100 + 10% = $110, but $110 − 10% = $99, not $100. Percentages do not reverse by subtraction — divide by 1.1, or use ÷11.

Ex GST or Inc GST? How to Read Australian Prices and Quotes

Australia has two pricing habits, and mixing them up is where most GST arguments start. Prices shown to consumers must include GST — a business is not allowed to advertise or quote you one figure and then add GST at invoice time, although the invoice itself may break the GST out as a separate line. Between businesses the custom flips: tradies and B2B suppliers usually quote "plus GST", because GST-registered customers claim the GST back and care about the before-GST price. So when a tradie quotes "$700 + GST", multiply by 1.1 — $770 is what will leave your account. Two more tips from people who learned the hard way: if you sell through an online platform or marketplace, check whether it adds GST on top of the price you set; and if a sole trader charges you GST, you can check their ABN at abr.business.gov.au — a business that is not registered for GST should not be charging it at all.

When to Use This Calculator — and When Not To

Use it for everyday Australian price work: turning a "plus GST" quote into the amount you will actually pay, adding 10% to your own quotes and invoices, pulling the GST out of a receipt for your records, and double-checking figures your software produces — even well-known accounting packages have shipped GST calculation bugs, and a quick ÷11 check catches them. It is not the right tool for a few jobs. GST on imports follows a different recipe — customs value plus freight, insurance and duty, then 10% on that bigger number — so check the ATO before relying on a figure for an import. Your BAS net position (GST collected minus GST credits on purchases) is a bookkeeping job across all your sales and expenses, not a one-line calculation. And GST-free or input-taxed items (basic food, residential rent, most financial services) have no 10% to add or remove in the first place.

Common Mistakes with Australian GST

The classic: subtracting 10% to remove GST. $110 − 10% gives $99 instead of the correct $100 — wrong by a dollar on every hundred, and the error grows with the amount. The only correct moves are ÷1.1 for the before-GST price or ÷11 for the GST itself. Second: expecting the GST on a receipt to be 10% of the total. It is 10% of the before-GST price, which makes it one eleventh (about 9.09%) of the total — so a $20 purchase shows $1.82 of GST, not $2.00. Third: trusting software blindly. Accounting packages have miscalculated 10% GST before, and experienced bookkeepers verify the GST line with price ÷ 11 by hand. Finally, remember that the GST you collect is not your money — you are holding it for the ATO, so set it aside as it comes in.

Australian GST Magic Numbers

One factor per task — multiply to add GST, divide to take it out.

Task	Factor
Add 10% GST to a price	× 1.1
Price without GST from a total	÷ 1.1
GST inside a total (official method)	÷ 11
GST on a GST-exclusive price	× 0.1

Registration Thresholds and Quick GST Reference

Who must register for GST in Australia, and the GST inside common GST-inclusive amounts — with official sources.

Who must register for GST
Sole trader	$75,000+
Company or partnership	$75,000+
Non-profit organisation	$150,000+
Taxi & ride-sourcing drivers	Any turnover

You have 21 days to register after crossing the threshold. Below it, registering is optional — some businesses register voluntarily to claim GST credits.

GST inside common amounts
Inc. GST	GST (÷11)	Ex. GST
$100.00	$9.09	$90.91
$200.00	$18.18	$181.82
$500.00	$45.45	$454.55
$1,000.00	$90.91	$909.09
$1,100.00	$100.00	$1,000.00

Sources: ATO – How GST works · Moneysmart – GST calculator · Tax, Super + You – GST calculator · Wikipedia – GST (Australia) — Rate last verified: 2026-06-11

Australian GST Calculator FAQ

Q1.How much is GST in Australia?

10%. The rate has been the same since GST started on 1 July 2000, and because it is a federal tax it is identical in every state and territory — NSW, Victoria, Queensland, WA and the rest. It applies to most goods and services, though GST-free items such as most basic food are excluded. Source: Australian Taxation Office.

Q2.How do I add GST to a price in Australia?

Multiply the price by 1.1. A "$700 + GST" quote becomes $700 × 1.1 = $770 including GST, and the GST component is $70. Equivalently, the GST alone is 10% of the before-GST price (multiply by 0.1): the government's worked example adds $100 of GST to a $1,000 price for a $1,100 total.

Q3.How do I work out the GST included in a price?

Divide the GST-inclusive price by 11 — the method the government's Moneysmart calculator describes. A $110 total contains $110 ÷ 11 = $10 of GST, so the price before GST was $100. It works for any amount: $550 contains $50 of GST, and $1,000 contains $90.91.

Q4.Why is the GST on my receipt not 10% of the total?

Because the 10% was charged on the price before GST, not on the total. The before-GST price is 100% and the total is 110%, so the GST is 10/110 of what you paid — one eleventh, or about 9.09%. That is why a $20 receipt shows $1.82 of GST rather than $2.00.

Q5.Why can't I just subtract 10% to remove GST?

Because subtracting 10% takes 10% of the bigger, GST-inclusive number. $100 + 10% = $110, but $110 − 10% removes $11 instead of $10 and leaves $99. The error grows with the amount. Always divide by 1.1 for the before-GST price, or divide by 11 for the GST itself.

Q6.Do advertised prices in Australia include GST?

Prices shown to consumers must include GST — a business cannot quote one figure and add GST on top at payment time, though the invoice may show GST as a separate line. Between businesses the custom flips: B2B suppliers and tradies usually quote "plus GST" because business customers claim the GST back. If you doubt whether a sole trader should be charging GST at all, look up their ABN at abr.business.gov.au.

Q7.When do I have to register for GST?

Once your GST turnover reaches $75,000 in a year ($150,000 for non-profit organisations), you have 21 days to register with the ATO. Taxi and ride-sourcing drivers must register regardless of turnover. Below the threshold, registration is optional — some businesses register voluntarily to claim GST credits on their purchases.

Q8.What items are GST-free in Australia?

Most basic food, some education courses and course materials, some medical, health and care products and services, exports, and menstrual products (removed from GST after the October 2018 agreement). Separately, residential rent and most financial services are input-taxed, which also means no GST is added. Processed food, restaurant meals and takeaway do carry the 10%.

Q9.Can tourists claim GST back when leaving Australia?

Yes, through the Tourist Refund Scheme (TRS). You can claim at the airport TRS counter if you spent A$300 or more (GST inclusive) with a single business (same ABN), bought the goods within 60 days of departure, and can show the original tax invoice. The refund does not cover consumables you have used up, or services such as hotels and flights.

Q10.Will the GST rate go up from 10%?

Nothing is scheduled. The rate has stayed at 10% for more than 25 years: a 2015 proposal to lift it to 15% and a 2019 push for 12.5% both stalled for lack of broad political support. Any change would need federal and state agreement, so this page tracks the official rate and shows the date it was last verified.

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