GST Calculator

The GST Calculator adds GST to a net price or removes GST from a GST-inclusive price using the correct rate for India, Australia, New Zealand, Canada and Singapore. It shows the net amount, the GST amount and the gross total, plus a visual price-stack and — where it applies — the full tax breakdown: India's CGST / SGST / IGST split and Canada's federal GST + provincial PST, QST or HST components.

What is GST?

GST (Goods and Services Tax) is a broad-based consumption tax added to the price of most goods and services. The business collects it from the customer at the point of sale and passes it on to the government. Because it is charged as a percentage of the price, you often need to either add GST onto a quoted net price or remove the GST already baked into a shelf price — which is exactly what this calculator does.

GST Formula

Adding GST is straightforward; removing it is where most people slip up.

Common mistake: to remove 18% GST you must divide the gross price by 1.18, not subtract 18% of it. Subtracting 18% of a GST-inclusive 1180 gives 967.60, but the true net is 1180 ÷ 1.18 = 1000. The gap grows with the rate.

GST Rates by Country

India: CGST, SGST and IGST

India's GST is a dual GST shared between the central and state governments. How it is split depends on where the buyer and seller are located:

• Intra-state supply (buyer and seller in the same state): the rate is split equally into CGST (Central GST) and SGST (State GST). An 18% sale becomes 9% CGST + 9% SGST.
• Inter-state supply (buyer and seller in different states): a single IGST (Integrated GST) is charged at the full rate — 18% IGST for an 18% sale.

The total tax the customer pays is identical either way; only the split between governments changes.

India's rates since 22 September 2025: most goods and services now fall into two slabs, 5% and 18%. A 40% rate applies to luxury and "sin" goods such as large cars, sugary drinks and, since 1 February 2026, cigarettes, pan masala and most other tobacco products. Gold and silver are taxed at 3%, and many essentials are 0%. The old 12% and 28% slabs are gone for almost everything, so an invoice or calculator that still uses them is out of date.

Canada: GST, PST, QST and HST

Every Canadian province pays the 5% federal GST. On top of that:

• GST-only — Alberta and the three territories charge just the 5% GST.
• GST + PST — British Columbia, Saskatchewan and Manitoba add a separate provincial sales tax (PST).
• GST + QST — Quebec adds the 9.975% Quebec Sales Tax (QST).
• HST — Ontario and the Atlantic provinces combine federal and provincial tax into a single Harmonized Sales Tax (13%–15%). Nova Scotia's HST dropped to 14% in April 2025.

This calculator always shows the 5% federal portion separately from the provincial portion, so you can see exactly where your tax goes.

How to Use This Calculator

1. Enter the amount: the net price for Add GST, or the GST-inclusive total for Remove GST.
2. Choose add or remove: select whether you are putting GST on or taking it off.
3. Pick your country and rate: for India choose the slab and intra/inter-state supply; for Canada pick the province; or choose Custom rate for any other percentage.
4. Click Calculate GST: see the net, GST and gross figures, the animated price-stack, and the component breakdown.

Frequently Asked Questions

How do I add GST to a price?

Multiply the net price by the GST rate to get the GST amount, then add it to the net price. For example, at 18% GST a net price of 1000 has GST of 1000 × 18 ÷ 100 = 180, giving a gross price of 1180. In one step, Gross = Net × (1 + rate ÷ 100).

How do I remove GST from a GST-inclusive price?

Divide the gross price by 1 plus the rate divided by 100. At 18% GST an inclusive price of 1180 has a net of 1180 ÷ 1.18 = 1000 and a GST portion of 180. Do not simply subtract 18% of the gross price, which gives the wrong answer.

What are the GST rates for India, Australia, New Zealand, Canada and Singapore?

Since 22 September 2025 India uses two main slabs, 5% and 18%, a 40% rate for luxury and sin goods, 3% for gold and silver, and 0% for many essentials. Australia charges 10%, New Zealand 15% and Singapore 9%. Canada charges a 5% federal GST plus a provincial tax, giving combined rates from 5% up to about 15% depending on the province.

What is the difference between CGST, SGST and IGST in India?

For a sale within the same state (intra-state), GST is split equally into Central GST (CGST) and State GST (SGST). For a sale between two states (inter-state), a single Integrated GST (IGST) is charged at the full rate instead.

How does Canadian GST, PST, QST and HST work?

Every province charges the 5% federal GST. Some provinces add a separate provincial sales tax (PST, or QST in Quebec), while others combine both into a single Harmonized Sales Tax (HST). Alberta and the territories charge only the 5% GST.

Is GST calculated on the price before or after other charges?

GST is normally applied to the net price of the goods or services, including any freight or handling that forms part of the supply, but before the GST itself. This calculator treats the amount you enter as the taxable base in Add GST mode.

Additional Resources

• Goods and Services Tax - Wikipedia
• Value-Added Tax - Wikipedia