$10.00
$100.00
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$10.00
$100.00
$110.00
0.1
Goods and Services Tax (GST) is a broad-based consumption tax levied on the supply of most goods and services. It operates similarly to VAT in that it is collected at each stage of the supply chain, with businesses claiming back the GST paid on their inputs, so the final tax burden falls entirely on the end consumer.
GST is the primary consumption tax in countries including Australia (10%), New Zealand (15%), Canada (5% federal), Singapore (9% as of 2024), and India (5%, 12%, 18%, or 28% depending on the goods category). In Canada, most provinces have a combined Harmonized Sales Tax (HST) that merges the federal GST with the provincial sales tax into a single rate.
This calculator handles both forward GST calculations (adding GST to an ex-GST amount) and reverse calculations (removing GST from a GST-inclusive amount). Businesses frequently need both: adding GST when pricing products or issuing invoices, and removing GST when reconciling GST-inclusive purchases for input tax credit claims.
Our GST Calculator supports any GST rate, making it equally useful whether you are in Australia, New Zealand, India, Singapore, or any other GST jurisdiction. Simply select your calculation direction, enter the amount and rate, and get instant results.
There are two calculation modes:
Adding GST (ex-GST amount to GST-inclusive amount):
$$\text{GST Amount} = \text{Ex-GST Amount} \times \frac{\text{GST Rate}}{100}$$
$$\text{GST-Inclusive Amount} = \text{Ex-GST Amount} \times \left(1 + \frac{\text{GST Rate}}{100}\right)$$
Removing GST (GST-inclusive amount to ex-GST amount):
$$\text{Ex-GST Amount} = \frac{\text{GST-Inclusive Amount}}{1 + \frac{\text{GST Rate}}{100}}$$
$$\text{GST Amount} = \text{GST-Inclusive Amount} - \text{Ex-GST Amount}$$
Example — Adding 10% GST to $500:
$$\text{GST} = 500 \times 0.10 = \$50$$
$$\text{Total} = 500 + 50 = \$550$$
Example — Removing 10% GST from $550:
$$\text{Ex-GST} = \frac{550}{1.10} = \$500$$
$$\text{GST} = 550 - 500 = \$50$$
The key insight is that removing GST requires dividing by (1 + rate), not multiplying by (1 - rate), which is a common error.
When adding GST, the Result Amount is the GST-inclusive price to charge customers or show on invoices. When removing GST, the Result Amount is the ex-GST (net) price for recording in your accounts or claiming input tax credits. The GST Amount in both cases represents the tax component. For input tax credit claims in Australia (BAS), use the ex-GST amount as the business expense and claim the GST Amount as the credit — provided the purchase is for a creditable business purpose.
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An Australian business with ex-GST revenue of $450 must charge $45 GST, issuing a tax invoice for $495 total.
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An Indian invoice for Rs.1,180 inclusive of 18% GST contains Rs.180 in GST and Rs.1,000 in net value.
Australia applies a single GST rate of 10% on most goods and services. Some items are GST-free (zero-rated), including most food, medical services, educational courses, and some financial services. Others are input-taxed (such as residential rent and financial supplies), where GST is not charged but input credits are also not claimable.
India's GST has multiple rate slabs: 0% (essential goods), 5% (daily necessities), 12% (standard goods), 18% (most services and goods), and 28% (luxury items, tobacco, automobiles). Many goods and services are exempt. India's GST is divided into CGST (Central) and SGST (State), or IGST for interstate supply.
In Australia, businesses with an annual turnover of $75,000 or more (or $150,000 for non-profits) must register for GST. In New Zealand, the threshold is NZD 60,000. Once registered, you charge GST on taxable sales, claim credits on business purchases, and report via periodic tax returns (e.g., BAS in Australia).
A tax invoice is a document issued by a GST-registered supplier that shows the GST amount separately. Customers need a valid tax invoice to claim input tax credits. In Australia, a tax invoice must show: seller's ABN, date, description of goods/services, GST amount or statement that the total includes GST, and both ex-GST and GST-inclusive amounts for transactions over $1,000.
Individuals cannot normally claim GST back on personal purchases. Only GST-registered businesses can claim input tax credits for GST paid on purchases used in carrying on their business. However, some countries offer tourist refund schemes where visitors can claim GST/VAT back on goods taken out of the country, such as Australia's Tourist Refund Scheme (TRS).
GST and VAT are functionally very similar — both are multi-stage consumption taxes where businesses collect tax on sales and claim credits for tax paid on purchases. The main difference is naming and minor implementation details. Countries like Australia, New Zealand, and Canada call it GST, while most of Europe and the UK use the term VAT. Some countries (like India and Canada) also have additional layers such as provincial sales taxes stacked on top of GST.
Roboculator Team
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