Free GST Calculator

Add or remove GST from any amount instantly. Supports Australian, New Zealand, Singapore, and Indian GST rates.

$
%
Pre-tax amount$100.00
GST (10%)$10.00
Total (incl. GST)$110.00

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How to Calculate GST

GST (Goods and Services Tax) is a consumption tax added to the price of goods and services. The calculation depends on whether you need to add GST to a base price or extract GST from a total amount.

Adding GST to an amount

To add GST, multiply the original amount by the GST rate. For Australian GST at 10%: GST = Amount x 0.10. The total is the original amount plus the GST.

Removing GST from an amount

To find the pre-GST amount from a GST-inclusive price, divide by (1 + GST rate). For 10% GST: Pre-tax = Total / 1.10. The GST component is the total minus the pre-tax amount.

GST Rates by Country

  • Australia: 10% GST on most goods and services
  • New Zealand: 15% GST
  • Singapore: 9% GST (increased from 8% in 2024)
  • India: 5%, 12%, 18%, or 28% depending on the category