GST Calculator
Print| Net Amount (Excl. Tax) | $0.00 |
| GST Tax Amount | $0.00 |
The Goods and Services Tax (GST) is a multi-stage indirect consumption tax levied on the sale of goods and services. Businesses use GST calculations to price consumer goods, issue tax invoices, and claim input tax credits (ITC), while consumers use them to determine actual tax amounts paid on purchases.
Our free GST Calculator calculates both GST Exclusive (adding tax to a net price) and GST Inclusive (extracting tax from a total price) across any statutory GST rate (e.g., 5%, 10%, 12%, 18%, or 28%).
How to Calculate GST (Inclusive & Exclusive)
GST calculations depend on whether you are adding tax to an initial net cost or removing tax from a final invoice total.
1. GST Exclusive Formula (Adding GST to Net Amount):
GST Tax Amount = Net Amount × ( GST Rate % / 100 )
Gross Total Amount = Net Amount + GST Tax Amount
2. GST Inclusive Formula (Extracting GST from Gross Amount):
GST Tax Amount = Gross Amount - [ Gross Amount / ( 1 + ( GST Rate % / 100 ) ) ]
Net Pre-Tax Amount = Gross Amount / ( 1 + ( GST Rate % / 100 ) )
Shortcut (10% GST Rate): GST Tax Amount = Gross Amount / 11
GST Inclusive vs. Exclusive Price Breakdown Table
The table below shows price breakdowns for a $100.00 base amount across standard international GST rates:
| Statutory GST Rate | Net Price (Exclusive Base) | GST Tax Amount Added | Final Gross Price | Extracted GST (from $100 Gross) |
|---|---|---|---|---|
| 5% GST | $100.00 | $5.00 | $105.00 | $4.76 |
| 10% GST (Australia / NZ) | $100.00 | $10.00 | $110.00 | $9.09 (Divide by 11) |
| 12% GST | $100.00 | $12.00 | $112.00 | $10.71 |
| 18% GST (Standard Services) | $100.00 | $18.00 | $118.00 | $15.25 |
Step-by-Step Calculation Examples
Example A: Calculating GST Exclusive (Adding 18% GST to a $500 Net Item)
- Net Price: $500.00
- GST Rate: 18%
- Step 1:
GST Tax Amount = $500 × 0.18 = $90.00 - Step 2:
Gross Price = $500 + $90 = $590.00
Example B: Calculating GST Inclusive (Extracting 10% GST from a $220 Receipt)
- Gross Total Receipt: $220.00
- GST Rate: 10%
- Step 1:
Net Pre-Tax Price = $220 / 1.10 = $200.00 - Step 2:
GST Tax Amount = $220 - $200 = $20.00(or$220 / 11 = $20.00)
Frequently Asked Questions (FAQ)
What is the difference between GST Inclusive and GST Exclusive?
GST Exclusive means the price listed does not yet include tax; GST must be added to reach the final price. GST Inclusive means the price listed already includes the GST tax amount in the total.
What is Input Tax Credit (ITC) in GST accounting?
Input Tax Credit allows registered businesses to subtract the GST tax they paid on raw materials and business purchases from the GST tax they collect on sales to customers, preventing double taxation.
How do I extract a 15% GST amount from a total price?
To extract 15% GST from a total inclusive price, divide the total price by 1.15 to find the net price, then subtract the net price from the total price to find the GST tax amount.