How to Use the GST Calculator
The GST Calculator handles Goods and Services Tax calculations for India, Australia, and Canada. For India, it calculates all GST slabs (5%, 12%, 18%, 28%) including the CGST/SGST split for intra-state transactions. For Australia, it applies the 10% flat GST rate. For Canada, it handles both the federal GST (5%) and combined HST rates by province.
Enter the amount and select your country and slab (for India) or province (for Canada) to instantly see the tax-exclusive price, GST amount, and tax-inclusive total. You can also work backwards — enter the GST-inclusive price to find the original pre-tax amount.
A critical nuance for India: GST is split between CGST and SGST for intra-state transactions (each half the total rate) or becomes IGST for inter-state transactions (the full rate paid to the central government). The calculator shows this breakdown to help with invoice preparation and filing.
📊 Worked Example
₹15,000 product in India at 18% GST (intra-state):
- Base amount: ₹15,000
- CGST (9%): ₹1,350
- SGST (9%): ₹1,350
- Total GST (18%): ₹2,700
- Invoice total: ₹17,700
Common Use Cases
- ✅ Creating GST-compliant invoices for Indian businesses
- ✅ Calculating GST-inclusive prices for Australian goods and services
- ✅ Working out Canadian HST by province for e-commerce
- ✅ Reverse-calculating the pre-GST price from a GST-inclusive amount
- ✅ Checking GST amounts on supplier invoices
- ✅ Planning pricing to include or exclude GST from customer-facing prices
Frequently Asked Questions
What are the GST slabs in India?
India has four main GST slabs: 5% (essential food items, transport), 12% (processed food, computers), 18% (most goods and services — the most common rate), and 28% (luxury goods, tobacco, cars). Some items are exempt (0%) including fresh vegetables, milk, and educational services.
What is the difference between CGST, SGST, and IGST?
For intra-state (within one state) transactions, GST is split: CGST goes to the central government and SGST goes to the state government, each at half the total rate. For inter-state transactions, IGST (Integrated GST) applies at the full rate, with the central government later distributing the state's share.
What is the GST rate in Australia?
Australia has a flat 10% Goods and Services Tax (GST) on most goods and services. Some categories are GST-free: basic food (fresh food, meat, bread), health and medical services, educational services, and exports. The GST-inclusive price is exactly 1.1× the base price.
Which Canadian provinces have HST instead of GST?
Ontario, New Brunswick, Newfoundland and Labrador, Nova Scotia, and Prince Edward Island use a combined Harmonised Sales Tax (HST) that merges federal GST and provincial sales tax into one rate (13–15%). Other provinces have separate provincial sales tax (PST) alongside the 5% federal GST.
Who needs to register for GST in India?
Businesses with annual turnover above ₹40 lakh (₹20 lakh in some states) for goods must register for GST. For services, the threshold is ₹20 lakh (₹10 lakh in some states). Inter-state suppliers and e-commerce sellers must register regardless of turnover. Registration is mandatory before filing GSTR returns.