GST calculator — add or remove GST
Add or remove GST at Australian, New Zealand, Indian, Singaporean and Canadian rates, with a multi-line invoice and export.
- Runs in your browser
- Nothing you enter is sent
- Free, no account
Net
A$1,000.00
GST
A$100.00
at 10%
Gross
A$1,100.00
- Net goods and services tax-free amount90.9%A$1,000.00
- GST at 10%9.1%A$100.00
The tax fraction of a gross amount at 10% is 10 / 110 = 0.0909.
Formula and working
GST due
tax = net × rate = 1,000 × 10% = A$100.00
Gross amount
gross = net × (1 + rate) = 1,000 × 1.1000 = A$1,100.00
Dividing by 1.10 is the only correct way to strip GST out of a gross amount. Subtracting 10% from the gross figure gives the wrong answer — it takes 10% of the larger number.
| Description | Rate | Net (excluding GST) | GST | Gross (including GST) |
|---|---|---|---|---|
| Consultancy — 10 hours | 10% | A$850.00 | A$85.00 | A$935.00 |
| Materials | 10% | A$124.50 | A$12.45 | A$136.95 |
Total net
A$974.50
Total GST
A$97.45
Total gross
A$1,071.95
| Rate | Net | GST | Gross |
|---|---|---|---|
| 5% | A$1,000.00 | A$50.00 | A$1,050.00 |
| 6% | A$1,000.00 | A$60.00 | A$1,060.00 |
| 9% | A$1,000.00 | A$90.00 | A$1,090.00 |
| 10% | A$1,000.00 | A$100.00 | A$1,100.00 |
| 12% | A$1,000.00 | A$120.00 | A$1,120.00 |
| 13% | A$1,000.00 | A$130.00 | A$1,130.00 |
| 15% | A$1,000.00 | A$150.00 | A$1,150.00 |
| 18% | A$1,000.00 | A$180.00 | A$1,180.00 |
| 28% | A$1,000.00 | A$280.00 | A$1,280.00 |
Assumptions
- Rate presets are static data held in the page as of 1 July 2026. Nothing is fetched, so rates cannot silently change — but they also cannot silently update. Confirm against your tax authority before you file anything.
- Reduced, zero and exempt categories differ by country and by product. Only the headline standard and common reduced rates are listed.
- Each invoice line is rounded to two decimals independently. Some jurisdictions require rounding the invoice total instead; the difference is at most a cent per line.
- Canadian provinces charge GST alone, GST plus a separate PST, or a combined HST. The presets cover GST and HST; a province with separate PST needs both rates entered as two lines.
- Nothing you enter is transmitted. Invoice figures stay in this browser tab.
The two shortcuts worth memorising
In Australia, GST is 10%, which makes the arithmetic unusually friendly:
- Add GST: multiply the ex-GST price by 1.1.
- Find the GST inside a total: divide by 11.
- Find the ex-GST price: divide the total by 1.1.
New Zealand's 15% is less tidy. Divide the inclusive total by 1.15 for the ex-GST price, and by 7.6667 for the GST itself. The three-sevenths shortcut people remember from the old 12.5% rate has been wrong since October 2010.
Rates in this calculator
| Country | Rate | Divide total by | Tax fraction of total |
|---|---|---|---|
| Australia — GST | 10% | 1.10 | 1/11 |
| New Zealand — GST | 15% | 1.15 | 3/23 |
| Singapore — GST | 9% | 1.09 | 9/109 |
| India — GST slabs | 5 / 12 / 18 / 28% | 1.05 – 1.28 | varies |
| Canada — GST | 5% | 1.05 | 1/21 |
| Canada — HST (Ontario) | 13% | 1.13 | 13/113 |
| Canada — HST (Atlantic) | 15% | 1.15 | 3/23 |
| Malaysia — SST (services) | 6% | 1.06 | 3/53 |
Stored in the page as static data with the date they were checked. This site makes no network requests, so nothing here is fetched live — confirm the current rate with your revenue authority before filing, and type a custom rate whenever you need one.
India's slab system
India does not have a single GST rate. Goods and services are assigned to slabs — most commonly 5%, 12%, 18% and 28% — by the GST Council, with some items zero-rated and a compensation cess on top of 28% for a short list of luxury and demerit goods. The applicable slab follows your HSN code for goods or SAC code for services.
The tax also splits by destination. A sale within a state is CGST plus SGST, each half the total rate; a sale across state lines is IGST at the full rate. That split affects how you report it, not how much it is, so the arithmetic above is the same in either case.
Canada: GST, PST and HST
Three regimes coexist. Alberta and the territories charge only the 5% federal GST. Ontario and the Atlantic provinces use a Harmonised Sales Tax that combines federal and provincial into one rate of 13% or 15%. British Columbia, Saskatchewan and Manitoba charge 5% GST plus a separate provincial sales tax, and Quebec charges GST plus QST.
For a separate-PST province, enter the two taxes as two lines in the invoice panel rather than adding the rates together — they are administered separately, and in Quebec the QST base rules differ from GST.
GST or VAT? Structurally the same tax
Both are broad-based consumption taxes collected at every stage of the supply chain, with businesses claiming credit for tax already paid on their inputs so that only the final consumer bears the cost. Australia, New Zealand, India, Canada and Singapore say GST; the UK, the EU and South Africa say VAT. The name is historical; the arithmetic on this page is identical either way.
Both are also quite different from a US sales tax, which is charged only at the final retail sale with no input credit mechanism at all.
Invoices and rounding
The multi-line panel handles a full invoice with a different rate per line, which matters for Indian slabs and for mixed supplies anywhere. Each line is rounded to the minor unit independently — standard practice in accounting software — and the totals are the sum of the rounded lines. Some authorities require the total to be rounded instead; the difference is at most one cent per line, but be consistent about which you use.
Registration thresholds
Australia requires GST registration above A$75,000 of turnover (A$150,000 for non-profits), New Zealand above NZ$60,000, and Singapore above S$1 million. Below the threshold, registration is usually optional — and it can still be worth doing if you sell mainly to other registered businesses, since they reclaim what you charge while you reclaim the GST on your own costs.
Everything runs on your device
Turnover, invoice values and client work stay in this browser tab. There is no server behind this page, no analytics and no third-party request, and the CSV, Excel and PDF exports are all generated locally. It works perfectly well with the network disconnected.
Questions
How do I work out GST from a GST-inclusive price?
For Australia’s 10% GST, divide the total by 11 to get the GST and by 1.1 to get the ex-GST price. For New Zealand’s 15%, divide by 7.6667 and 1.15 respectively. The calculator does it for any rate.
Which Indian GST rate applies?
Since 22 September 2025 India has two main slabs, 5% and 18%, plus 40% for luxury and sin goods, set per category by the GST Council. All three are presets; pick the slab your HSN or SAC code falls into.
How does Canadian GST, HST and PST work?
Some provinces charge 5% federal GST alone, some add a separate provincial PST, and others use a combined HST: 13% in Ontario, 14% in Nova Scotia and 15% in the other Atlantic provinces. GST and HST presets are included; for a province with separate PST, enter the two taxes as two lines.
Is GST the same as VAT?
Structurally yes — both are broad-based consumption taxes collected at each stage with credit for tax already paid. The name and the rules differ by country; the arithmetic is identical.
Are these rates fetched live?
No. This site never makes a network request. Rates are stored in the page with the date they were checked, and you can always type your own.