GST Calculator - Add or Remove Goods and Services Tax From Any Price
Goods and Services Tax is used by Australia, Canada, India, New Zealand, Singapore, and dozens of other countries. GST = Net Price x GST Rate. Total = Net + GST. Reverse: Net Price = Gross Price / (1 + GST Rate).
GST Rates Around the World
Australia: 10% flat rate (key exemptions: basic food, medical services, educational courses). New Zealand: 15% broad-based. Singapore: 9% (increased from 8 percent in January 2024). Canada: 5% federal GST (provinces add 0-10% bringing combined to 5-15%). India: 5%, 12%, 18%, or 28% depending on goods/services category.
The Formula Explained
Adding GST (Australia 10%): Emma's photography job fee: AUD $2,400. GST: $2,400 x 0.10 = $240. Total invoice: $2,640.
Removing GST (New Zealand 15%): Retailer total: NZD $230. Net: $230 / 1.15 = $200. GST: $30. Australian GST fraction: 1/11 of gross. NZ GST fraction: 3/23 of gross.
| Country | GST Rate | Net Price (example) | GST Amount | Gross Price |
|---|---|---|---|---|
| Australia | 10% | AUD $1,000 | AUD $100 | AUD $1,100 |
| New Zealand | 15% | NZD $1,000 | NZD $150 | NZD $1,150 |
| Singapore | 9% | SGD $1,000 | SGD $90 | SGD $1,090 |
| India (standard) | 18% | INR 1,000 | INR 180 | INR 1,180 |
| Canada (Ontario HST) | 13% | CAD $1,000 | CAD $130 | CAD $1,130 |
How to Use This Calculator on CalcAdvisor.com
Access the calculator at https://www.calcadvisor.com/calculators/gst-calculator.
3 Real-World Examples
Example 1: Emma, Australian Freelance Photographer, Invoicing Clients
Fee: AUD $2,400. GST: $240. Total invoice: $2,640. Emma holds $240 until her quarterly BAS, then remits to the ATO. She also claims input GST on her business purchases.
Example 2: Daniel, Ontario Business Owner, Navigating HST on a Mixed Purchase
Produce (zero-rated): CAD $380. Restaurant equipment: $1,650. HST on equipment (13%): $214.50. Total invoice: $2,244.50. Daniel claims $214.50 as input tax credit on his HST return.
Example 3: Ravi, Indian Consultant, Managing IGST on Inter-State Transaction
Service invoice: INR 1,20,000. Maharashtra to Karnataka - inter-state IGST at 18%: INR 21,600. Total: INR 1,41,600. Ravi collects and remits INR 21,600 through the GST portal.
Common Mistakes to Avoid
- Calculating reverse GST by multiplying gross by rate rather than dividing.
- Applying GST to exempt or zero-rated items.
- Not registering for GST when crossing the threshold.
- Confusing GST-inclusive and GST-exclusive pricing in quotes.
- Missing GST credits on capital expenditure.
- Incorrectly handling GST on partially private-use items.
- Not issuing tax invoices for GST-registered transactions.
Final Thoughts
Handle any GST calculation instantly at https://www.calcadvisor.com/calculators/gst-calculator.