GST Calculator

Calculate GST (Goods and Services Tax) for Australia, New Zealand, Canada, India, and Singapore. Add GST to a price or extract GST from an inclusive total.

Part of our Business Calculators collection.

GST Calculator

Free online calculator

Country / Rate

Custom GST Rate (%)

Amount ($)*

Mode

How to Use This Calculator

1
Select your country or enter a custom rate.
2
Enter the amount.
3
Choose to add or remove GST.
4
See GST amount and total instantly.

GST Formulas

Add GST:    Total = Price × (1 + Rate%)
Remove GST: Pre-GST = Total / (1 + Rate%)
GST Amount = Total − Pre-GST Price

Example Calculation

Example: Add 10% GST to $100 (Australia)

Inputs

country: 10amount: 100mode: add

Result

GST: $10 | Total: $110

$100 × 1.10 = $110. GST = $10.

Frequently Asked Questions

How do I find GST in a GST-inclusive price?

GST = Total × Rate / (1 + Rate). For $110 at 10%: $110 × 0.10 / 1.10 = $10 GST.