Free gst calculator
Add or remove GST in two seconds. Enter an amount, pick a rate (India 5/12/18/28%, Australia 10%, NZ 15%, Canada 5%), and choose add or remove. The calculator returns the net price, the GST amount, and the gross price — plus the CGST/SGST split for India — updated live, as you type.
On this page15 sections
Estimates only, based on the values you enter. Not tax advice.
Results are estimates. Consult a professional.
What is GST (Goods and Services Tax)?
GST — Goods and Services Tax — is a broad-based consumption tax added to the price of most goods and services. It is collected at each stage of the supply chain but ultimately paid by the final consumer, which is why it shows up as a line on your receipt. India, Australia, New Zealand, Canada, Singapore, and dozens of other countries run a GST; the European Union and the UK run the same idea under the name VAT. This GST calculator does the two jobs you actually need: it adds GST to a pre-tax price, or removes (reverses) GST out of a tax-inclusive price.
The rate that applies depends on the country — and in India, on the product's tax slab. A single rate (10% in Australia, 15% in New Zealand, 5% federal in Canada, 9% in Singapore) covers most goods, while India uses a tiered structure of 5%, 12%, 18% and 28%. Pick your rate, choose add or remove, and the calculator returns the net price, the GST amount, and the gross price instantly.
GST formula — how GST is calculated
There are two directions, and getting them mixed up is the single most common GST mistake. Which one you need depends on whether the amount you start with already includes GST.
Adding GST vs removing GST
Adding GST (forward / exclusive)
You start with a net, pre-tax figure and put GST on top. A supplier quoting a business price ex-GST, or a freelancer setting an invoice, adds GST. At 18% on ₹1,000: GST is ₹180, and the gross becomes ₹1,180.
Removing GST (reverse / inclusive)
You start with a tax-inclusive total and pull the GST back out — useful when you need the taxable value for bookkeeping, or want to know the tax buried in a shelf price. Here you divide, not subtract. A ₹1,180 inclusive price at 18% becomes ₹1,180 ÷ 1.18 = ₹1,000 net, leaving ₹180 of GST.
A worked example using the GST calculator
A consultant in Mumbai is billing a client ₹1,000 for services taxed at the 18% slab. Here is how they use the calculator, step by step, to build a compliant invoice.
- Choose the mode. The ₹1,000 fee is a pre-tax (net) amount, so they leave the toggle on Add GST.
- Enter the amount. They type 1000 into the amount field.
- Set the rate. They tap the 18% preset (or type 18).
- Read the result. GST = ₹1,000 × 18% = ₹180. Gross = ₹1,000 + ₹180 = ₹1,180.
- Split it for the invoice. The client is in the same state, so the ₹180 splits into CGST ₹90 + SGST ₹90.
| Line | Amount |
|---|---|
| Taxable value (net) | ₹1,000.00 |
| CGST @ 9% | ₹90.00 |
| SGST @ 9% | ₹90.00 |
| Total GST @ 18% | ₹180.00 |
| Invoice total (gross) | ₹1,180.00 |
An intra-state invoice: 18% GST shown as CGST 9% + SGST 9%.
GST rates by country and India slab
Most countries that run a GST use a single standard rate. India is the exception, with a four-tier slab system that assigns each category of goods and services to a rate. Set the calculator to your country's rate — or to the India slab your product falls under.
| Country / region | GST rate | Notes |
|---|---|---|
| India | 5% / 12% / 18% / 28% | Four-slab system; 18% is the most common |
| Australia | 10% | Flat since 1 July 2000 |
| New Zealand | 15% | Flat since 1 October 2010 |
| Canada (federal) | 5% | Provinces add PST/HST on top (up to 15%) |
| Singapore | 9% | Raised to 9% in January 2024 |
Standard GST rates by jurisdiction. Sources: national tax authorities (see Sources below).
India's GST slabs at a glance
| Slab | Typical goods & services |
|---|---|
| 5% | Household essentials, packaged food, economy transport, small restaurants |
| 12% | Processed food, business-class air travel, some apparel and footwear |
| 18% | Most services, electronics, soaps, capital goods — the default slab |
| 28% | Luxury and 'sin' goods — cars, tobacco, aerated drinks, high-end items |
Illustrative; exact classification is set by the GST Council and changes over time.
CGST, SGST and IGST — how the split works
In India, the headline GST rate is split between governments depending on whether the sale crosses a state border. The total tax is identical either way — only the labelling and who collects it changes.
GST-inclusive vs GST-exclusive pricing
A GST-exclusive price is the amount before tax — the figure a business often quotes to other businesses, who can reclaim the GST anyway. A GST-inclusive price already contains the tax, which is what consumers pay at the till; in many countries the displayed shelf price (and India's MRP) must be inclusive.
| GST-exclusive | GST-inclusive | |
|---|---|---|
| Printed price | $100.00 | $110.00 |
| GST (10%) | $10.00 | $10.00 |
| You pay | $110.00 | $110.00 |
Same transaction, two ways of quoting it (Australia, 10%). The tax is identical; only the starting number differs.
Match the calculator to the price you have: an exclusive price means use Add GST; an inclusive price means use Remove GST. Quote the wrong one and you are either over-charging the customer or under-collecting the tax.
Who pays GST — and input tax credit
GST is collected in stages but is designed to fall only on the final consumer. A registered business charges GST on its sales (output tax) and claims back the GST it paid on its purchases (input tax credit), remitting only the difference to the government. So while every link in the chain handles GST, none of them ultimately bears it — the end buyer does.
That is why a business cares about the net (exclusive) figure — its real cost and revenue — while a consumer only sees the gross (inclusive) price. Registration thresholds vary by country (for example, India's standard threshold is ₹40 lakh of turnover for goods; Australia's is A$75,000), below which a business generally need not register or charge GST.
GST vs VAT vs sales tax
GST and VAT are essentially the same mechanism under different names — a multi-stage tax with input credits — used in different regions. US-style sales tax is different: it is charged only once, at the final retail sale, with no input-credit chain. The arithmetic for a single transaction, though, is the same percentage-on-price, so the same calculator logic applies.
- GST — India, Australia, NZ, Canada, Singapore. Multi-stage with input tax credit.
- VAT — EU, UK, and much of the world. Same mechanism, different name.
- Sales tax — US states. Single-stage, collected only at retail.
If you are working in a VAT or US sales-tax context instead, the matching tools are the VAT calculator and the sales tax calculator.
Sources and methodology
GST rates and the CGST/SGST/IGST split follow each jurisdiction's tax authority: India's GST Council and CBIC, the Australian Taxation Office (10%), New Zealand's Inland Revenue (15%), the Canada Revenue Agency (5% federal), and Singapore's IRAS (9%). The calculator applies the standard add and remove formulas shown above and rounds for display only; rates can change, so confirm the current rate for your transaction.
Australian Taxation Office — GST.Central Board of Indirect Taxes and Customs (CBIC) — GST.Frequently asked questions about the free gst calculator
About this GST calculator
This GST calculator runs entirely in your browser. Every figure you enter stays on your device — nothing is sent to a server, logged, or shared. To add GST it multiplies your net amount by the rate; to remove GST it divides the inclusive total by (1 + rate) to back out the tax, and it splits the result into CGST and SGST for India — all updating instantly as you type.
Calculators Cloud offers 400+ free tools with no sign-up. For other consumption taxes see the VAT calculator and sales tax calculator, or browse the full calculator directory.